[8] [8] MONDAL I, KRISHNAPURA N. A 2 GHz bandwidth, 0.25~1.7 ns true-time-delay element using a variable-order all-pass filter architecture in 0.13 m CMOS[J]. IEEE Journal of Solid-State Circuits, 2017, 52(8): 2180-2193. DOI: 10.1109/JSSC.2017.2693229.

[9] [9] GARAKOUI S K, KLUMPERINK E A M, NAUTA B, et al. Compact cascadable g(m)-C all-pass true time delay cell with reduced delay variation over frequency[J]. IEEE Journal of Solid-state Circuits, 2015, 50(3): 693-703. DOI: 10.1109/JSSC.2015.2390214.

[10] [10] HU F, MOUTHAAN K. A 1~20 GHz 400 ps true-time delay with small delay error in 0.13 m CMOS for broadband phased array antennas[C]//2015 IEEE MTT-S International Microwave Symposium. Phoenix, AZ, USA: IEEE, 2015: 1-3. doi: 10.1109/MWSYM.2015.7166834.