CN103378869A - Transceiver sharing multi-winding transformer - Google Patents

Abstract

The invention discloses a transceiver sharing a multi-winding transformer, comprising: a multi-winding transformer, which comprises a first winding, a second winding and a third winding which are mutually surrounded and independent; a power amplifier coupled to the multi-winding transformer; and a low noise amplifier coupled to the multi-winding transformer; wherein, in the transmission mode, the multi-winding transformer is used for converting a transmission signal from the power amplifier and transmitting the signal through an antenna; and in a receiving mode, the multi-winding transformer is used for converting a receiving signal from the antenna and outputting the signal to the low noise amplifier. The transceiver of the invention can utilize the multi-winding transformer to reduce the area and achieve good matching, thereby reducing the cost and improving the efficiency.

Description

Transceivers sharing multi-winding transformers

technical field

The invention relates to a transceiver, in particular to a wireless communication transceiver sharing a multi-winding transformer.

Background technique

In the application field of wireless communication, the three main units of the system are transmitter, antenna, and receiver. Generally speaking, the wireless signals transmitted in the air are all single-ended signals, but the differential circuit inside the transmitter is a differential signal, so the transmitter must use its internal The differential signal is converted into a single-ended signal before it can be sent to the air through the antenna; on the other hand, the receiver must first convert the single-ended signal received by the antenna into a differential signal before it can be sent to the air. The internal low noise amplifier (low noise amplifier, LNA) is used. The operation of this type of signal conversion is realized by a balanced-to-unbalanced (balun) transformer, and the transmission end and the receiving end each have a transformer component, which will occupy a large chip area if implemented on the chip.

With the development of integrated circuit technology towards system on chip (SoC), integrated transformers have replaced traditional discrete transformers and are widely used in radio frequency integrated circuits (RFICs). However, passive components in integrated circuits, such as inductors or their transformers, often occupy a large chip area; therefore, reducing the number of passive components and the area used in transceiver integrated circuits has always been an important technical issue.

Contents of the invention

Therefore, one of the purposes of the present invention is to propose a transceiver (transceiver) that can share an integrated multi-winding transformer at the receiving end and the transmitting end, thereby successfully connecting the low noise amplifier at the receiving end and the power amplifier at the transmitting end. , achieve good matching, greatly reduce the chip area and have good performance.

According to an embodiment of the present invention, it provides a transceiver formed on an integrated circuit substrate, which includes: a multi-winding transformer, which includes a first winding, a second winding, and a winding independent of each other. a third winding; a power amplifier coupled to the multi-winding transformer; and a low-noise amplifier coupled to the multi-winding transformer transceiver; A transmit signal from the antenna is transmitted through an antenna; and in a receive mode, the multi-winding transformer is used to transform a receive signal from the antenna and output to the low noise amplifier.

According to an embodiment of the present invention, it provides a transceiver, which includes: a multi-winding transformer formed on an integrated circuit substrate, which includes a first winding, a second winding, and a winding independent of each other. a third winding; a power amplifier coupled to the multi-winding transformer; and a low noise amplifier coupled to the multi-winding transformer; wherein the multi-winding transformer converts a differential transmit signal from the power amplifier into a Single-ended transmission signal; the multi-winding transformer transforms a single-ended reception signal into a differential reception signal, and outputs it to the low-noise amplifier.

The transceiver of the present invention can use the multi-winding transformer to reduce the area and achieve good matching, thereby reducing the cost and improving the efficiency.

Description of drawings

FIG. 1 is a schematic circuit diagram of a transceiver according to an embodiment of the invention.

FIG. 2A is a layout diagram of the winding circuit of the integrated transformer according to this embodiment.

Fig. 2B is a cross-sectional structure diagram obtained along the line A-A' according to the embodiment of Fig. 1A.

FIG. 2C is a circuit layout diagram of the first winding according to the embodiment of FIG. 2A .

FIG. 2D is a circuit layout diagram of the second winding according to the embodiment of FIG. 2A .

FIG. 2E is a circuit layout diagram of the third winding according to the embodiment of FIG. 2A .

FIG. 3 is a schematic diagram of a transceiver circuit according to a first example of the present embodiment, wherein the low noise amplifier has a common-gate circuit structure.

FIG. 4 is a schematic diagram of a transceiver circuit according to a second example of the present embodiment, wherein the low noise amplifier has a common-source circuit structure.

Wherein, the reference signs are explained as follows:

100 transceivers

10 substrate/chip

20 multi-layer structure

201 first floor

203 second floor

202 insulating layer

110 multi-winding transformer

112 first winding

113 first middle tap

114 second winding

116 third winding

117 second middle tap

P ₁ ⁺ /P ₂ ⁺ Positive terminal of transformer primary coil

P ₁ ^- /P ₂ ^- Negative terminal of transformer primary coil

S ₁ ⁺ /S ₂ ⁺ Positive terminal of transformer secondary coil

S ₁ ^- /S ₂ ^- Negative terminal of transformer secondary winding

120 power amplifier

V _dd DC power supply

130/131/132 LNA

_Vb bias

140 antenna

Detailed ways

The features, purpose, functions, and technical means used to achieve the present invention will be described and illustrated in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic circuit diagram of a transceiver according to an embodiment of the invention. The transceiver 100 can be connected to an antenna 140, and the operation state of the transceiver 100 can be switched between transmission and reception modes. The transceiver 100 can be integrated on a wafer or a substrate through an integrated circuit process, and includes a multi-winding transformer 110 , a power amplifier 120 , and a low noise amplifier 130 . The multi-winding transformer 110 is a balun transformer with multiple windings to provide format conversion for signals used in communication systems.

Fig. 2A is a winding circuit layout diagram of the multi-winding transformer 110 according to this embodiment, and Fig. 2B is a cross-sectional structure diagram obtained along the line A-A' according to the embodiment of Fig. 2A. In this embodiment, the multi-winding transformer 110 is formed in a metal layer 20 in a multi-layer structure on a semiconductor substrate 10, which includes a first winding 112, a second winding 114, and a The third winding 116 to form a transformer with three windings. Wherein the first, second and third windings surround each other to form a multi-winding structure. In another embodiment, the transformer 110 may further include a guard ring (guard ring) 70, the guard ring 70 is preferably a stacked guard ring, that is, a guard ring composed of multiple layers of metal materials, formed on The multi-layer structure 20 around the multi-winding structure and the substrate 10 is used to isolate the electromagnetic effect or noise of the transformer 110 and reduce the mutual electric influence between the windings and other components outside the protective ring.

The first winding 112 is basically disposed in a first layer 201 of the multilayer structure 20 . The first winding 112 can be a multi-turn coil (coil) structure; with the circuit layout diagram of the first winding 112 shown in FIG. The first coil, the two connecting ends, and a first center tap (center tap) 113 . The lines of the first coil are basically parallel to each other except for the bridge portions crossing each other. The first coil can be adjusted or jumped to the upper or lower layer of the metal layer in the above-mentioned bridging part, so as to keep the continuity of the coil path of the first winding 112, that is, the first winding 112 A coil is spatially separated from each other without forming a short circuit. In order to increase the density of the coil patterns, the first coils may be helically intertwined circuit patterns. The first middle tap 113 is a tap drawn from the center of the coil of the first winding 112 for the use of differential signals; Connecting end forms 0 degree, 90 degree, 180 degree, or other appropriate arbitrary angles, is convenient to connect the external circuit with the shortest path; And the first middle tap 113 also can utilize the mode of jumper wire so that it is not connected with the bridging part or the coil other parts of the short circuit.

The second winding 114 is also basically disposed in the first layer 201 of the multilayer structure, that is, located in the same layer as the first winding 112 . The second winding 114 can be a multi-turn coil structure; with the circuit layout diagram of the second winding 114 shown in FIG. end. The circuit layout of the second winding 114 is similar to the description of the first winding 112 in the previous paragraph, and will not be repeated here. Wherein, the circuit patterns of the first winding 112 and the second winding 114 are basically square or rectangular; , or increase the application of space and chip area.

The first winding 112 and the second winding 114 are substantially arranged in the same metal layer (the first layer 201 ), the purpose of which is to form an electromagnetic coupling in the lateral direction between the two, so as to It is formed to provide the operation function of the transformer or to perform the transformation operation of the signal. Therefore, the circuit patterns of the first winding 112 and the second winding 114 are spatially separated from each other and substantially parallel to each other, but the number of coils of the first coil can be different from that of the second coil, so as to According to actual needs, the appropriate primary/secondary coil number ratio (turn ratio) of the transformer is provided; and the number of coils of the second winding 114 can also be more than the number of coils of the first winding 112, the The outermost coil of the second winding 114 may also be on the periphery of the first winding 112 . In addition, in order to improve the efficiency of electromagnetic coupling, an interdigitated (inter-digital) arrangement can be formed between the first and second coils in this embodiment, as shown in FIG. The densest coil pattern is formed on the chip area. Wherein, the part where the circuit patterns of the first winding 112 and the second winding 114 may be cross-connected can also be separated from the first winding 112 and the second winding 114 by means of a jumper as mentioned above.

The third winding 116 is basically disposed in the second layer 203 of the multi-layer structure, that is, on a different metal layer from the first winding 112 and the second winding 114, and an insulating layer 202 may be disposed on the second layer 203. Between the first layer and the second layer, the first layer 201 and the second layer 203 are spaced apart. The third winding 116 can be a coil structure with multiple turns; the circuit layout diagram of the third winding 116 as shown in FIG. end, and a second middle tap 117. The circuit layout pattern of the third winding 116 is also similar to the description of the first winding 112 in the previous paragraph, and will not be repeated here. The circuit pattern of the third winding 116 can be the same as or different from the circuit pattern of the first winding 112, but the lead-out direction of the connection end of the third winding 116 can be rotated at a specific angle with the connection end of the first winding 112, so as to facilitate winding The I/O connection ends are connected to other circuits with the shortest path, which can reduce the parasitic components of the transmission line and facilitate the optimization of circuit layout. As shown in FIG. 2A , the circuit pattern of the third coil and the second coil is to form a vertical electromagnetic coupling between them to form another transformer for signal conversion. The third winding 116 shown in FIG. 2E is the circuit pattern of the first winding 112 shown in FIG. 2C rotated 90 degrees counterclockwise; but not limited thereto, and other appropriate angles can also be rotated. The circuit patterns of the third winding 116 and the first winding 112 are spatially separated from each other, and are basically parallel to each other except for the connection end, the middle tap, and the bridge or crossing portion, and all of the present embodiment The third and first coils are basically arranged to overlap up and down, as shown in Figure 1, but not limited to this, there can also be a slight displacement between the two, or only partially overlap, or non-central symmetry line settings. The second middle tap 117 is a tap pulled out from the center of the coil of the third winding 116 for the use of differential signals. 90 degrees, 180 degrees, or other suitable arbitrary angles.

As shown in FIGS. 2A and 2B , the position where the second winding 114 and the third winding 116 are projected onto the substrate 10 in a plan view is located within the position where the outermost coil of the first winding 112 is projected onto the substrate 10 in a plan view. That is to say, the layout of the first winding 112 can surround the layout of the second winding 114 and the third winding 116; that is, the outermost coil of one winding will surround the coils of the other two windings. In addition, in the sectional view of FIG. 2B, the second layer 203 is located above the first layer 201; but not limited thereto, the second layer 203 may also be located below the first layer 201, that is, The third winding 116 may also be located below the first winding 112 . The third winding 116 can also be formed above or below the first winding 112 by using more than two layers of metal. The first winding 112 and the second winding 114 can also be formed by more than two layers of metal. In some embodiments, the electromagnetic coupling among the first winding 112 , the second winding 114 and the third winding 116 may be complete or partial vertical coupling or horizontal coupling.

Therefore, FIG. 2A shows a transformer with three windings, and its equivalent circuit diagram can be drawn in the dotted box of the multi-winding transformer 110 in FIG. 1 . The first winding 112 , the second winding 114 , and the third winding 116 are mutually surrounded and independent in the layout diagram. The first winding 112 and the second winding 114 form a first transformer through electromagnetic coupling in the lateral direction, the first winding 112 is used as the primary coil of the first transformer, and its positive terminal is P ₁ ⁺ and negative terminal is P ₁ ⁻ , and the second winding 114 serves as the secondary coil of the first transformer, and its positive terminal is S ₁ ⁺ and its negative terminal is S ₁ ⁻ . Since the first winding 112 has the first middle tap 113 , the first transformer can convert the differential signal operated by the differential circuit inside the transmitter of the wireless communication system into a single-ended signal transmitted in the air. On the other hand, the second winding 114 and the third winding 116 form a second transformer through electromagnetic coupling in the vertical direction, and the second winding 114 is also used as the primary coil of the second transformer, and its positive terminal is P ₂ ⁺ and the negative connection terminal is P ₂ ⁻ , and the third winding 116 is used as the secondary coil of the second transformer, the positive connection terminal is S ₂ ⁺ and the negative connection terminal is S ₂ ⁻ . Wherein, the second winding 114 can be shared by the first and second transformers. Because the third winding 116 has the second middle tap 117, the second transformer can convert the single-ended signal into a differential signal; thus, the receiver can, after receiving the single-ended signal transmitted from the antenna, It is converted to a differential signal by the second transformer and used by the low noise amplifier. That is to say, the multi-winding transformer 110 can realize the operation of a balanced-unbalanced transformer for receiving and transmitting wireless communication signals. In addition, the lead-out direction of the primary coil connection end of each transformer can be arranged at 180 degrees, 90 degrees, 45 degrees, or other appropriate arbitrary angles with its secondary coil connection end, so that the winding input/output connection ends are connected by the shortest path On the active circuit, the parasitic components of the transmission line can be reduced to facilitate the optimization of circuit layout.

As shown in Figure 1, the primary winding of the first transformer is connected to the power amplifier 120, and its secondary is connected to the antenna 140; Two connection ends of the winding 114 are connected to the antenna 140, and its negative connection S ₁ ⁻ is grounded. In addition, a primary coil of the second transformer (same as the secondary coil of the first transformer) is connected to the antenna 140, and its secondary is connected to the low noise amplifier 130; that is, the two connection ends of the second winding 114 Connected to the antenna 140 , the two terminals of the third winding 116 are connected to the low noise amplifier 130 .

In this embodiment, since the first winding 112 and the second winding 114 are located on the same layer in the multi-layer structure, electromagnetic coupling in the lateral direction can be performed for signal conversion; and the first winding 112 has the The first middle tap 113 is available for the power amplifier 120 . On the other hand, the second winding 114 and the third winding 116 are located in different layers of the multi-layer structure, and can perform electromagnetic coupling in the vertical direction to perform signal conversion; and the third winding 116 has the second middle split Connector 117 is available for the low noise amplifier 130 . Therefore, the integrated transformer 110 is a balun transformer with two spatially independent center taps.

The circuit operation of the wireless transceiver of this embodiment is described below. When the transceiver operates in the transmission mode, the multi-winding transformer 110 is used to transform the transmission signal from the power amplifier 120 and transmit it through the antenna 140; for example, using the first winding 112 and the second winding 114 A first transformer is formed to transform the transmit signal. The first winding 112 serves as a differential coil for the primary of the first transformer, and the second winding 114 serves as a single-ended coil for the secondary of the first transformer. The differential signal of the power amplifier 120 is converted through the first transformer. It is a single-ended signal, and then output to the antenna 140 to be sent out. On the other hand, when the transceiver operates in the receiving mode, the multi-winding transformer 110 is also used to transform the received signal received from the antenna 140 and output to the low noise amplifier 130; for example, using the second winding 114 and The second transformer formed by the third winding 116 transforms the received signal. The second winding 114 serves as a single-ended coil for the primary of the second transformer, and the third winding 116 serves as a differential coil for the secondary of the second transformer. The single-ended signal from the antenna 140 is transmitted through the second transformer It is converted into a differential signal and provided to the low noise amplifier 130 as its input signal. In this structure, since the winding coils coupled to the power amplifier 120 and the low noise amplifier 130 are spatially independent, when designing the circuit layout of the two, the power amplifier 120 and the low noise amplifier 130 can be designed respectively. The circuit characteristics of the amplifier 130 are optimized, and the impedance of the antenna 140 is converted to its optimum impedance for the first and second transformers respectively through the ratio of the number of coils between the windings. In addition, the line width of each winding can also be adjusted according to the noise figure of the low noise amplifier 130 and the power density of the power amplifier 120 .

In this embodiment, the low noise amplifier 130 may adopt a common gate or common source circuit structure. FIG. 3 is a schematic diagram of a transceiver circuit according to a first example of the present embodiment, wherein the low noise amplifier 131 has a common-gate circuit structure. The first middle tap 113 is connected to the DC power supply V _dd of the power amplifier 120; wherein, the voltage range of V _dd depends on the application of the power amplifier, and the second middle tap 117 is connected to ground to provide the power amplifier. The current grounding path of the low noise amplifier 131 can improve the disadvantage that the existing balanced-unbalanced transformer cannot be connected to the low noise amplifier with a common gate structure. Since the low noise amplifier of the common gate structure has the characteristics of broadband matching, this structure does not need to add additional matching components on the printed circuit board, which is beneficial to reduce the manufacturing cost.

On the other hand, FIG. 4 is a schematic diagram of a transceiver circuit according to a second example of the present embodiment, wherein the low noise amplifier 132 has a common-source circuit structure, and has an input transistor with a bias voltage of V _b , and the voltage V _b The multi-winding transformer 100 is connected to the gate of the input transistor to determine its bias voltage, and its voltage range depends on the requirements or applications of the low noise amplifier circuit. The first middle tap 113 is connected to the DC power supply V _dd of the power amplifier 120 , and the second middle tap 117 is connected to the bias voltage V _b of the low noise amplifier 132 ; thus, at least two can be saved. One AC coupling capacitor (ACcoupling capacitor), thus saving the chip manufacturing area and cost of components.

In this embodiment, since the integrated transformer 110 as a balanced-unbalanced transformer is connected to the power amplifier 120 and the winding coil of the low-noise amplifier 130 are located in different metal layers in the multi-layer structure, so in the integrated circuit layout The connection port of the input/output of the winding coil can be designed in different directions, for example, the connection between the third winding 116 of the integrated transformer 110 and the first winding 112 or the second winding 114 as shown in Fig. 1 The terminals are spaced at an angle of 90 degrees or perpendicular to each other; thus, the traces connected to the power amplifier 120 and the low noise amplifier 130/131/132 will not intersect, which is beneficial to the optimization of the layout of the integrated circuit.

In addition, in the transceiver of another embodiment, the multi-winding transformer 110 may also be formed as an on-chip transformer separately and formed on an integrated circuit substrate. The power amplifier 120 and the low noise amplifier 130 are discrete components respectively, and are assembled together with the transformer 110 on the circuit board to form a transceiver with the functions of the above-mentioned embodiments. Regarding the transformer 110 , the power amplifier 120 and the low noise amplifier 130 , please refer to the descriptions of the foregoing embodiments, and details will not be repeated here.

According to the above embodiments and descriptions, the transceiver of the present invention can use the multi-winding transformer to reduce the area and achieve good matching, thereby reducing cost and improving performance. However, what is described above is only a preferred embodiment of the present invention and should not be used to limit the scope of the present invention.

Claims (14)

1. a transceiver is formed on the ic substrate, it is characterized in that it comprises:

One multi winding transformer, its comprise mutually around and independently one first winding, one second winding, and the tertiary winding;

One power amplifier is coupled to this multi winding transformer; And

One low noise amplifier is coupled to this multi winding transformer;

Wherein, when transfer mode, this multi winding transformer transmits signal in order to change from one of this power amplifier, and transmits by an antenna; And when receiving mode, this multi winding transformer receives signal in order to change from one of this antenna, and exports this low noise amplifier to.

2. transceiver as claimed in claim 1 is characterized in that, this multi winding transformer utilizes this first and second winding to change this transmission signal, and utilizes this second and third winding to change this reception signal.

3. transceiver as claimed in claim 1 is characterized in that, this first and second winding utilizes side-coupled this transmission signal that changes.

4. transceiver as claimed in claim 3 is characterized in that, this second and third winding utilizes vertical coupled this reception signal that changes.

5. transceiver as claimed in claim 1 is characterized in that, it is a monofocal signal with this transmission signal by a differential type signal transition that this multi winding transformer utilizes this first and second winding, to transmit by this antenna.

6. transceiver as claimed in claim 5 is characterized in that, this multi winding transformer utilizes this second and third winding to convert this reception signal to a differential type signal by a monofocal signal, and exports this low noise amplifier to.

7. transceiver as claimed in claim 1 is characterized in that, this first and the tertiary winding in have respectively tap in.

8. transceiver as claimed in claim 1 is characterized in that, at the layout of this multi winding transformer, a winding in this first, second and third winding centers on two other winding in this first, second and third winding.

9. a transceiver is characterized in that, comprising:

One multi winding transformer is formed on the ic substrate, its comprise mutually around and independently one first winding, one second winding, and the tertiary winding;

One power amplifier is coupled to this multi winding transformer; And

One low noise amplifier is coupled to this multi winding transformer;

Wherein, this multi winding transformer will be that a monofocal transmits signal from the differential type transmission signal transition of this power amplifier; It is that a differential type receives signal that this multi winding transformer receives signal transition with a monofocal, and exports this low noise amplifier to.

10. transceiver as claimed in claim 9 is characterized in that, this multi winding transformer utilizes this first and second winding to change this transmission signal, and utilizes this second and third winding to be used to change this reception signal.

11. transceiver as claimed in claim 10 is characterized in that, this first and second winding is formed in the identical metal level.

12. transceiver as claimed in claim 11 is characterized in that, this second winding is formed in the different metal levels from this tertiary winding.

13. transceiver as claimed in claim 9 is characterized in that, this first and the tertiary winding in have respectively tap in.

14. transceiver as claimed in claim 10 is characterized in that, this second and third winding is overlooked the top outer coil that the position that is projected to this substrate is positioned at this first winding and is overlooked within the position that is projected to this substrate.

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