JPS59128465A - Microwave radio meter - Google Patents

Abstract

PURPOSE:To realize a high sensitive radio meter without imparting influence to the posture of a satellite, by applying shift control to a plurality of phase shifters corresponding to a plurality of fixed element antennas. CONSTITUTION:Receiving waves of which the phases are different at every element antenna 1 are converted to IF by mixer 3. At this time, the phase with high frequency voltage supplied to each mixer 3 through an electric energy distributor 5 is controlled by each phase shifter 6 and synthesized by an electric energy synthesizer 9 so that the phases of noise radio waves arriving from specific directions come to the same phase in IFA8. In this case, the noise radio waves from specific directions are synthesized and the detection signal due to a square detector 10 is proportional to the intensity of the noise electric energy from each specific direction and, when the phases of the phase shifters 6 are successively controlled by a phase controller 7 to change an observation direction, the scanning of an observation region is enabled without imparting influence to the posture of a satellite not at all.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microwave radiometer that is mounted on an artificial satellite and used to detect sea surface temperature and atmospheric components. Most conventional microwave radiometers mechanically change the beam direction of the antenna in order to increase the sensitivity, reduce the electric loss of the antenna, and observe a wide area on the ground. However, the method of mechanically changing the direction of the antenna has the disadvantage that it has a large effect on the attitude of the satellite and makes it difficult to use a large antenna. On the other hand, in a few cases, so-called phased array antennas have been used, but due to the loss of the phase shifter, it is not possible to increase the sensitivity sufficiently, making it impossible to increase the observation accuracy. This invention was made to improve these conventional problems, and aims to realize a highly sensitive microwave radiometer without affecting the attitude of the satellite. . This will be explained below with reference to the drawings.

In the figure, (1) is a plurality of element antennas that are the main components of the microwave radiometer, and (3) is a mixer.

(4) is a local oscillator, (5) is a power divider, and (6) is a phase shifter.

(7) is a phase controller, (8) is an intermediate frequency amplifier, (9)
is a power combiner, and ttU is a square law detector.

In the above configuration, the noise electricity radiated from the observation object is received by each element antenna, but the phase of the received wave differs for each element antenna (1) depending on the direction of the observation object as seen from the antenna. ing. This received wave is converted into an intermediate frequency by a mixer (3), but at this time, it is supplied from one local oscillator (4), and a power divider (5) is sent to each mixer.
The phase of the high frequency voltage distributed by the phase shifter (6) is controlled by the phase shifter (6).

The power combiner (9) is configured so that the phases of the noise radio waves arriving from a specific direction are in the same phase within the intermediate frequency amplifier (8).
), the noise voltage in the specific direction mentioned above is synthesized, and the signal detected by the square law detector (11) becomes proportional to the strength of the noise power in the specific direction mentioned above.Then, the phase shift By sequentially controlling the phase of the satellite (6) with the phase controller (7) and changing the observation direction, it is possible to change the observation area without affecting the attitude of the 9 satellite at all since there are no mechanical or moving parts. It becomes possible to scan.

In addition, in a configuration of 9 or more, unlike a normal phased array, there is no phase shifter on the element antenna side, so it is possible to reduce antenna feeding loss and obtain a highly sensitive microwave radiometer. .

As mentioned above, the microwave radiometer of this invention can be mounted on nine artificial satellites without affecting the attitude control system, so it is possible to obtain a sensor with high distance resolution by mounting a large antenna. Great effects can be obtained, such as the ability to

[Brief explanation of the drawing]

The figure is a block diagram of the microwave radiometer according to the present invention.
is a phase shifter, (7) is a phase controller, (8) is an intermediate frequency amplifier, (9) is a power combiner, and aω is a square law detector. Agent Shin Kuzuno −

Claims (1)

[Claims] A plurality of fixed element antennas mounted on a satellite, a mixer provided corresponding to each antenna, a power combiner connected to the mixer through a plurality of corresponding intermediate frequency amplifiers, and an output of the power combiner. a square law detector connected to the end, a plurality of phase shifters connected to the mixer and corresponding to the element antennas, a phase controller for controlling the plurality of phase shifters, and a phase shifter connected to the plurality of phase shifters. a power divider;
A microwave radiometer comprising a local oscillator that provides a local oscillation signal to the power divider.