Design of Ultra-wideband True-Time Delay Multi-function Chip

Based on the demand for equipment such as aerospace and satellite communications, the ultra wideband true-time delay multi-function chip (MFC) is designed in this paper. Moreover, the digital and microwave circuits are integrated in the MFC, which contains T/ R SPDTs, a 5 bit digitally controlled true-time delay(TTD), a 5 bit digitally controlled attenuator(ATT) two TWT amplifiers,equilizer and digital circuit. Characterized with compact size of 4.5 mm * 5.0 mm * 0.07 mm, the MFC is fabricated on GaAs E/ D PHEMT technology. The test results on wafer show that the MFC provides 10~310 ps with an interval of 10 ps and 1~31 dB with an interval of 1 dB in the frequency range of 3~17 GHz. The test results show that the measured gain is more than 2 dB,and the 1 dB compressed output power P1dB_Tx is more than 12 dB in transmitting mode;while in receiving mode,the test gain is more than 2 dB,and the 1 dB compressed output power P1dB_Rx is more than 10 dB. The input and output VSWRs are better than 1.7 on the whole bandwidth for all states. The +5 V DC power consumption is better than 130 mA, and the -5 V DC power consumption is less than 12 mA. The root mean square (RMS) of ATT and phase variation is reduced to 1.4 dB and ±8°for all states. The root mean square (RMS) of TTD and insertion variation is reduced to 3 ps and ±1 dB for all states.