Broadband Cnc Delay Line Chip Developed

Wireless communication often demands wideband performance for multi-channel operation and steering multiple moving targets. Driven by the demand of the wireless communication market,there is great interest in the development of broadband,high delay-time accuracy, large delay-time GaAs MMIC solutions. Wideband digital true time delay (TTD) are the core chip for microwave T/R systems. Small size, light weight, high reliability make MMIC digital true time delay have been widely used in various electronic systems.This paper describes the operating principle, circuit design, MMIC fabrication and testing techniques for broadband digital true time delay. The digital true time delay development is based on PHEMT material, MMIC process and the design method combining schematic diagram and electromagnetic simulations. All time-delay bits use a topology with constant-R networks in the delay path.High delay-time accuracy, large delay-time have been achieved.Measurement results for a typical chip are presented.The main specifications of the GaAs MMIC digital true time delay are as follows:Frequency range: 2 ~ 18GHz; number of bits: 6bits; insertion loss≤22.0dB; total delay time 315ps; VSWR≤2.5:1.The test results satisfy the design requirement, verify the GaAs MMIC design theory, and provide important references for design improvement in the future.and the theory analysis according to the test results are also given.