| Phased array antenna technology is widely used in the field of radar communications.In order to obtain more distant and wider space scanning angles,conventional phase shifters cannot be used.Timed array technology based on true-time delay has better resolution because it has higher bandwidth and thus has more accurate phase shift resolution.The true-time delay technology proposed so far mostly uses the structure of an artificial transmission line and uses a large number of inductors.This article explores the use of active analog circuit architectures to achieve ultra-wideband true-time delays.The overall circuit design consists of four parts,an active delay cell design,switching entire column circuit design,digital control circuit design,and matching circuit design.The active delay unit constitutes the main part of the delay line to replace the traditional LC network and uses active inductance to optimize the chip design area.The switch array circuit is designed as a path selector that is controlled by digital signals and changes the delay output by changing the external digital signal.In addition,the switch selection circuit is combined with the active delay unit,and the delays between the two circuits are offset to increase the flatness of the delay.And both use inductive peaking technology to expand bandwidth.The overall circuit realizes a digitally controlled analog delay line with small area,large range,high integration,and wide frequency band.Using TSMC65 lp CMOS technology design a true-time-delay lines based on active inductor and the chip area is 343×400μm2.The TT,SS,and FF process angle delay line delay ranges are 18ps-54 ps,21.6ps-67.6ps,and 14.6ps-46.4ps respectively,and the delay resolutions are 5.5ps,4.6ps,and 6.5ps,respectively.3GHz-15 GHz ultra-wideband,delay jitter is less than 15%.The operating voltage is 1.5V and the operating current is 14.2 mA.In this paper,a delay-based modern artificial transmission line structure based on active inductance is designed.With less inductance,the true-time delay of ultra-wideband is realized,which has certain significance for delay line designing in the future. |
