The Development Of Ka Band Amplifier

In the millimeter-wave system, millimeter-wave amplifier plays an extremely importantstatus and role. Its performance has a direct impact on the performance of the wholemillimeter-wave system. After taking full account of the millimeter-wave amplifier’sheat dissipation and assembly technology, this paper develops three Ka-bandmillimeter-wave amplifiers: Ka-band drive amplifier, Ka-band power amplifier andKa-band power combining amplifier.Firstly, the paper develops a Ka-band drive amplifier with HMMC-5040chip. Thetest results show that the drive amplifier has good input and output reflectioncoefficients during20GHz~37.5GHz band, a gain basically about18dB, and1dBcompression point output power above14dBm, with the peak of17.1dBm; But during37.5GHz~40GHz band, its S parameters deteriorate, and1dB compression point outputpower also falls rapidly.Then develops a Ka-band power amplifier with TGA4516chip. The results show that,during31GHz~37GHz band its input and output reflection coefficients meet therequirements basically, its gain is also between14dB~15dB, saturated output power isabove27dBm. All of these achieve the design requirements.Finally, this paper develops a Ka-band power combining amplifier with XL1000chip.At the beginning of design, the paper analyzes the impact of various factors on thecombining efficiency, and discusses in detail the advantages and disadvantages of thevarious power combining schemes and circuit forms, according to these chooses apower combining scheme with small size, easy achievement.Then briefly introduces the substrate integrated waveguide’s structure andcharacteristics, figures out its size, simulates a transition structure of substrate integratedwaveguide to microstrip line and two right-angle turn structure, then respectivelysimulates T-type and Y-type and deformed Y-type this three kinds of two-way powerdivider, after comparing with their performances designs a two-way powerdividing/combining circuit with T-type structure, and designs a four-way power dividing/combining circuit with T-type and Y-type structure. The test results of two-waypower dividing/combining circuit show that during33GHz~37GHz band its input andoutput reflection coefficients are below-12.5dB, and insertion loss is1.15dB or so.In the last develops a Ka-band power combining amplifier based on the two-waypower dividing/combining circuit, the test results show that during33GHz~37GHz bandit has low input and output reflection coefficients, a gain above14dB, saturated outputpower above11dBm, and it is estimated combining efficiency is about77%, basicallycomplies with the design requirements.