C-band GaAs dual-channel amplitude and phase multifunctional chip integrated with digital serial to parallel converter

A 5.8 GHz to 6.8 GHz C-band dual-channel amplitude and phase multifunctional chip was developed based on 0.15-μm GaAs enhancement-mode pseudomorphic high electron mobility transistor (E-mode pHEMT) process. The chip integrates 7-bit digitally controlled attenuator, gain compensation low noise amplifier, 6-bit digitally controlled phase shifter, power divider, and 30-bit digital serial-to-parallel converter. The integrated serial-to-parallel converter can control the attenuation and phase shift, and is also applied for recognition of chip address. The measured results show that in the reference state, the gains of the two channels are 0 dB to −0.5 dB and −0.15 dB to 0.42 dB, and their measured noises are less than 6.38 dB. In the attenuation state, the attenuation root mean square (RMS) errors of channel 1 and channel 2 are less than 0.35 dB and 0.34 dB, and the associated parasitic phase RMS errors are less than 2.5°and 2.45°, respectively. In the phase shift state, the phase RMS errors of channel 1 and channel 2 are less than 2.27° and 2.36°, and the corresponding parasitic amplitude RMS errors are lower than 0.27 dB. The presented chip exhibits the characteristics of large attenuation bit, high accuracy of attenuation and phase shift, small parasitic amplitude RMS error and parasitic phase RMS error, and a high integration level.