A Wideband GAAS 6-Bit True-Time Delay MMIC Employing On-Chip Digital Drivers

This paper describes a 2-20 GHz 6-bit True-Time Delay. A total equivalent electrical length in air of 43.5 mm (145 ps) is achieved over a 2-20 GHz bandwidth. Digital drivers and a serial-to-parallel converter are integrated on the same MMIC. The ED02AH 0.2 ¿m PHEMT process from OMMIC is used. The time delay elements are realised using constant-R networks. The three smallest bits make use of a self-switched version of the constant-R networks while the 3 largest bits use a topology with single-pole double-throw (SPDT) switches and constant-R networks in the delay path. Measurement results for a typical chip are presented.