A Study On Microwave T/R Module

Active phased array radar has many advantages, such as quick beam scanning, multi-beam forming, spatial power combining, simultaneous searching, tracking, identification, imaging, and guidance of multi-target. As such, it has been widely applied in missile-defense systems, airborne radar systems, electronic warfare systems, communications and navigation systems,and medical detection systems.T/R module is one of the essential building blocks in active phased array radar. It is therefore very important to study T/R module for active phased array radar. In this paper, miniaturization of T/R module at Ku band is studied. Topics include1) Overall layout of the T/R module at Ku band according to the specified performance indicators.2) Design of a novel waveguide-microstrip conversion structure with double-prob. Signals propagates along the same direction in both waveguide and microstrip by using this structure. In addition, it makes significant contribution to size reduction of the T/R module because of its integrated function power division. Simulation shows that its insertion loss is only 0.1d B in the frequency range of 15~18GHz.3) Design of transmitting and receiving channels sharing vector modulator for amplitude and phase modulation.4) Design of four-way power dividers in only four-layer Ferro’s A6 S dielectric substrate whose insertion loss is only 6.4 d B in the frequency of 15 ~ 18 GHz.5) Design of balanced I-Q vector modulators in the frequency of 14~18GHz by using WIN Semiconductors company’s 25.0mm Ga As p HEMT process line.Each vector modulator comprises nine Lange coupler, a power divider and eight transistors. The final size of a vector modulator is 2400μm×1600μm.6) Packaging based on LTCC multilayer circuit.The final size of the T/R module is 72mm×18mm×79mm. The output power of each transmission channel is greater than 41.4 d Bm, the gain of each receive channel is greater than 25.6d B, and the noise figure is less than 3.46 d B.