Broadband Multiport Amplifier consisting of 4 x 4 Butler Matrices Designed in Microstrip Technique

A broadband, fully integrated 4-channel Multiport Amplifier (MPA) operating at 1 GHz center frequency has been presented in this paper. Designed MPA consists of two 4 x 4 Butler matrices and amplifying blocks based on ADL5611 amplifiers offered by Analog Devices. To obtain broad operational bandwidth, Butler matrices are composed of coupled-line sections. Moreover, the circuitry has been designed in the microstrip technique to simplify the integration of passive and active parts of the multiport amplifier. The described circuit has been proven theoretically with circuit simulation, then designed, simulated electromagnetically, and manufactured.