Design And Implementation Of Microwave Low Noise Amplifier Modules

Microwave low noise ampliifer (LNA) is a key component of receiver system ofcommunication, satellite, radar, electronic countermeasure and remote measuring. With therapid development of the radio technology, especially the implementation of some widebandcommunication system，it greatly expands the demands to the microwave wideband low noiseamplifier. So，the microwave broadband low noise amplifier has got great development. Themajor difficulties in achieving microwave wideband low noise amplifier are the design ofwideband matching network and the controlling of gain flatness.In this dissertation，firstly we birefly introduce the application，developments of LNAboth at home and abroad. Some parameters and their measurement methods are described indetail in the following. Then, the principle of design and impedance matching are explained,the wideband microwave LNA is described, including the ampliifer structures and the theory.Basing on the design pirncipals，three LNA modules are designed using the ADSsotfware of Agilent, fabricated and measured. With the p-HEMT ATF-54143of Avago，twonarrowband LNA modules applying to GPS and Beidou satellite navigation system aredesigned respectively. The GPS one has the measured results:43mA working current,30dBgain in band，±0.43dB gain flatness. The Beidou one has the measured results:41mAworking current,30dB gain in band,土0.17dB gain flatness. The two LNA modules have thecharacteirstics of lower working current, lower noise figure, higher gain, and good portmatching.A wideband LNA module working at l-2GHz is achieved with the same p-HEMTATF-54143of Avago. The matching is achieved with micrstirp elements and lumped elementstogether, which convenients the circuit tuning. It gets good gain flatness by adapting drainparallel negative feedback. The module measured results:100mA working current，30dB gainin band,土0.8dB gain lfatness，NF<1.56dB. The design demands are achieved.At last we make a summarization on the above work and look into the following work inthe future. The dissertation shares the design experiences, which is helpful to microwavelower noise amplifier module and microwave circuit design.