CN204464433U

CN204464433U - For the braodband directional coupler of 4G mobile communication

Info

Publication number: CN204464433U
Application number: CN201420623966.6U
Authority: CN
Inventors: 徐立勤; 仲进
Original assignee: Nanjing Post and Telecommunication University
Current assignee: Nanjing Post and Telecommunication University; Nanjing University of Posts and Telecommunications
Priority date: 2014-10-24
Filing date: 2014-10-24
Publication date: 2015-07-08
Anticipated expiration: 2024-10-24

Abstract

The utility model provides the braodband directional coupler for 4G mobile communication, relates to the coupler that a kind of communication technical field uses.The utility model coupler comprises medium substrate, underlying metal floor, top layer microstrip branch line coupling unit, the micro-band of top layer L-type matching network in parallel unit and bottom defect ground structure unit, the bandwidth of coupler is widened by connecting micro-band L-type open circuit in parallel minor matters matching unit at each port of microstrip branch line coupler, the adding of defect ground structure in coupler ground plate, widen coupler bandwidth further.Frequency range of the present utility model covers the LTE frequency range of domestic three large operators, can be used for 4G mobile communication.The utility model broadband couple device cellular construction is simple, has symmetry; Moderate dimensions, cost of manufacture is cheap.

Description

For the braodband directional coupler of 4G mobile communication

Technical field

The utility model relates to the coupler that a kind of communication technical field uses, and specifically refers to a kind of braodband directional coupler for 4G mobile communication.

Background technology

Along with TD-LTE (that is: timesharing Long Term Evolution) commercial licence plate and FDD-LTE (that is: Long Term Evolution) test the granting of licence plate, China formally enters 4G communication era.Following domestic 4G mobile communication trend will be TD-LTE and FDD-LTE combination network, and the wide-band coupler covering TD-LTE and FDD-LTE frequency range is then one of critical component realizing networking.

The distribution of current domestic TD-LTE frequency range: China Mobile is 1880-1900MHz, 2320-2370MHz, 2575-2635MHz; CHINAUNICOM is 2300-2320MHz, 2555-2575MHz; China Telecom is 2370-2390MHz, 2635-2655MHz.The distribution of FDD-LTE frequency range: China Telecom is 1755-1785MHz and 1850-1880MHz; CHINAUNICOM is 1955-1980MHz and 2145-2170MHz.According to these situations, a wide-band coupler covering 1.75 ~ 2.75GHz frequency range can find application in TD-LTE and FDD-LTE combination network.

For the frequency band covering problem of coupler during TD-LTE and FDD-LTE two kinds of standard combination networks in domestic 4G mobile communication, the directional coupler that a kind of structure is simple, have broadband properties, be convenient to making is proposed, for the coupler exploitation of domestic 4G mobile communication provides technological reserve.

Summary of the invention

The purpose of this utility model is to provide a kind of braodband directional coupler for 4G mobile communication, and coupler volume of the present utility model is moderate, structure simple, effectively can realize the fusion with radio circuit.

The utility model adopts following technical scheme:

A kind of braodband directional coupler, comprises medium substrate, underlying metal floor, top layer microstrip branch line coupling unit, the micro-band of top layer L-type matching network in parallel unit and bottom defect ground structure unit;

Described underlying metal floor unit and bottom defect ground structure unit, printing is arranged on the bottom of medium substrate;

Described top layer microstrip branch line coupling unit and the micro-band of top layer L-type matching network in parallel unit, printing is arranged on the top layer of medium substrate, the micro-band of top layer L-type in parallel matching network unit is connected with each input of top layer microstrip branch line coupling unit, and the micro-band of top layer L-type in parallel matching network unit is micro-band L-type open circuit in parallel minor matters match circuit;

Bottom defect ground structure unit is corresponding up and down with the micro-band of top layer L-type in parallel matching network unit, and is respectively four groups; Described bottom defect ground structure obtains by etching on underlying metal floor.The material of described medium substrate to be dielectric constant be 4.4 epoxy glass cloth laminated board FR4.

Underlying metal floor, for ground connection; Top layer microstrip branch line coupling unit, in order to realize leading directly to, being coupled and isolation features; The micro-band of top layer L-type matching network in parallel unit is in order to widen coupler bandwidth; Bottom defect ground structure unit increases the bandwidth of operation of coupler further.

The utility model coupler has four ports, its port A (input) adds signal, distribute according to a certain percentage at port B (straight-through end) and port C (coupled end) as required, port D (isolation end) does not have signal to arrive, and loads matched load.

As preferably, the bottom defect ground structure described in coupler of the present utility model is that the defect ground structure series connection of five dumbbell shapes obtains.

Braodband directional coupler of the present utility model utilizes printed circuit board technology or integrated circuit technology to make, medium substrate designs top layer broadband couple device circuit and bottom layer ground plate, the symmetry up and down of top layer micro-band L-type matching network in parallel unit and bottom defect ground structure unit is ensured by above-mentioned means, the operating characteristic of adjustment coupler, realizes frequency coverage and the broadband properties of coupler.

The utility model beneficial effect:

The utility model coupler adopts classical microstrip branch line coupler, has volume little, is easy to the advantage integrated with other radio circuits.Widen the bandwidth of coupler by connecting micro-band L-type open circuit in parallel minor matters matching unit at each port of microstrip branch line coupler, then widen coupler bandwidth further to reach the effect covering whole 4G frequency range by etching the defect ground structure corresponding with matching unit on ground plate.The dielectric-slab of the utility model coupler adopts common epoxy glass cloth laminated board (FR4), and cost is low, has very strong practicality.

Add hierarchic structure in the matching network of coupler of the present utility model, give and regulate the performance of coupler to bring larger flexibility.

The adding of defect ground structure in coupler ground plate of the present utility model, greatly widen the bandwidth of coupler.

Coupler structure full symmetric of the present utility model, structure is simple, and manufacture craft is simple and easy; There is wideband operating characteristic, and volume is moderate, with low cost.

Accompanying drawing explanation

Fig. 1 is the top layer stereogram of the utility model coupler.

Fig. 2 is the bottom stereogram of the utility model coupler.

Fig. 3 is the vertical view of the utility model coupler.

Fig. 4 is the upward view of the utility model coupler.

Fig. 5 is the utility model coupler bottom defect ground structure unit and the upper and lower corresponding situation schematic diagram of the micro-band of top layer L-type in parallel matching network unit.

Fig. 6 is the input return loss characteristic figure of the utility model coupler.

Fig. 7 is the insertion loss schematic diagram of the utility model coupler.

Fig. 8 is the degree of coupling schematic diagram of the utility model coupler.

Fig. 9 is the isolation schematic diagram of the utility model coupler.

Figure 10 is the phase place schematic diagram that the utility model coupler leads directly to end.

Figure 11 is the phase place schematic diagram of the utility model coupler coupled end.

Specific embodiments

Below in conjunction with accompanying drawing, technical solutions of the utility model are described in further detail:

As shown in Figure 1, Figure 2, Figure 3, Figure 4, the utility model coupler structure is as follows: coupler is produced on medium substrate 1, is made up of top layer broadband couple device unit and bottom layer ground unit; Top layer broadband couple device unit is made up of top layer microstrip branch line coupling unit 3 and the micro-band of top layer L-type matching network in parallel unit 5, and bottom layer ground unit is made up of underlying metal floor unit 2 and bottom defect ground structure unit 4.

As shown in Figure 3, four ports 6 can arbitrarily set input, straight-through end, coupled end and isolation end.As shown in Figure 5, port A (input) adds signal, distribute according to a certain percentage at port B (straight-through end) and port C (coupled end) as required, port D (isolation end) does not have signal to arrive, and loads matched load.

Bottom defect ground structure unit is corresponding up and down with the micro-band of top layer L-type in parallel matching network unit, as shown in Figure 5.

Wide-band coupler of the present utility model, the micro-band of top layer L-type matching network in parallel unit 5 is made up of L-type microstrip line.Bottom defect ground structure unit 4 is in series by the defect ground structure of five dumbbell shapes.Concrete structure size is as follows: L-type microstrip line two branch line length is respectively 40 millimeters and 35 millimeters, and width is all 0.5 millimeter; The width of defect ground structure unit is 2.5 millimeters, and length is 35 millimeters.

Medium substrate 1 according to relative dielectric constant be 4.4, thickness is 0.8 millimeter of design.

The coupler input return loss utilizing electromagnetic simulation software to calculate, result as shown in Figure 6: the return loss for the input of wide-band coupler in 1.75 ~ 2.75GHz of 4G mobile communication can be less than-10dB.1.75 ~ 2.75GHz frequency range covers domestic TD-LTE and FDD-LTE frequency range.

As shown in Figure 7, the degree of coupling of coupler as shown in Figure 8 for the insertion loss of coupler.With reference to the accompanying drawings 7 and accompanying drawing 8 visible, the coupler power that straight-through end and coupled end export in 1.75 ~ 2.75GHz frequency range is roughly equal.

As shown in Figure 9, coupler has good isolation to the isolation of coupler in 1.75 ~ 2.75GHz frequency range.

As shown in Figure 10, the phase place of coupled end as shown in figure 11 for coupler straight-through end phase place.Coupler straight-through end and phase difference of coupled end in 1.75 ~ 2.75 frequency ranges be about ± and 90 °.

Wide-band coupler of the present utility model is functional, covers the 2.4GHz place frequency range of TD-LTE and FDD-LTE frequency range and WLAN, and structure is simple, is easy to processing and fabricating.

Claims

1. a braodband directional coupler, is characterized in that: comprise medium substrate (1), underlying metal floor (2), top layer microstrip branch line coupling unit (3), bottom defect ground structure unit (4), the micro-band of top layer L-type matching network in parallel unit (5);

Described underlying metal floor (2) and bottom defect ground structure unit (4) print the bottom being arranged on medium substrate (1);

Described top layer microstrip branch line coupling unit (3) prints with the micro-band of top layer L-type matching network in parallel unit (5) top layer being arranged on medium substrate (1), the micro-band of top layer L-type in parallel matching network unit (5) connects with each input of top layer microstrip branch line coupling unit (3), and the micro-band of top layer L-type in parallel matching network unit (5) is micro-band L-type open circuit in parallel minor matters match circuit;

The material of described medium substrate (1) is epoxy glass cloth laminated board.

2. braodband directional coupler according to claim 1, is characterized in that, described bottom defect ground structure unit (4) is dumbbell shape series connection defect.

3. braodband directional coupler according to claim 1, is characterized in that, adds hierarchic structure in the micro-band of described top layer L-type matching network in parallel unit (5).

4. braodband directional coupler according to claim 1, is characterized in that, described bottom defect ground structure unit (4) is corresponding up and down with the micro-band of top layer L-type in parallel matching network unit (5) position.

5. braodband directional coupler according to claim 4, is characterized in that, described bottom defect ground structure unit (4) is four groups with the micro-band of top layer L-type matching network in parallel unit (5).