Computer-Aided Design, Analysis and Optimization of HMIC SOP Broadband Balanced Amplifier

The purpose of this paper is to present a complete design and analysis of new HMIC 3.5-4.5 GHz broadband balanced amplifier modules using microstrip technology. Two different modules are designed and analyzed. Each module is implemented in a single substrate. The first module used Lange couplers as power splitters and combiners while the second used branch couplers. The components of the modules are designed using full-scale computer simulation program, performed by the author and named as MSDES, which takes fully into account all the discontinuities included in the microstrip lines; while the modules are analyzed and optimized using APLAC V7.61 software. A short and efficient CAD procedure for the broadband amplifier design is introduced. The first step is to design an initial narrowband high-gain microstrip amplifier at a center frequency equal to 4 GHz. The second step is to optimize the initial lengths and widths of the input and output microstrip-matching circuits to get the broadband amplifier over the range 3.5-4.5 GHz. The analyses of both narrow and broadband amplifiers are introduced in addition to the complete analysis of the designed 3.5-4.5 broadband balanced amplifier modules. The analysis of the designed balanced amplifier modules shows better efficiency and good performance. The complete AC schematic diagrams of the designed balanced amplifier modules are presented. These modules can be used in many applications including sensors, pulse Doppler communications, airborne radars, traffic control radars and satellite communications.