학술논문

A 0.2–2 GHz Time-Interleaved Multistage Switched-Capacitor Delay Element Achieving 2.55–448.6 ns Programmable Delay Range and 330 ns/mm2 Area Efficiency
Document Type
Periodical
Source
IEEE Journal of Solid-State Circuits IEEE J. Solid-State Circuits Solid-State Circuits, IEEE Journal of. 58(8):2349-2359 Aug, 2023
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Computing and Processing
Delays
Clocks
Switches
Radio frequency
Bandwidth
Capacitors
Repeaters
Broadband
low-noise amplifier
programmable delay element
radar
self-interference cancellation
switched-capacitor
true-time delay
Language
ISSN
0018-9200
1558-173X
Abstract
Simulation of radar returns, full-duplex systems, and signal repeaters require hundreds of ns of programmable broadband radio frequency (RF) delay in the signal path to simulate large distances in the case of radar returns, for signal cancellation in full-duplex, and for isolation from reflections in signal repeaters. However, programmable broadband RF delay has been limited to ones of ns due to challenges in miniaturization with low loss and low power consumption. In this work, we present a 0.2–2 GHz digitally programmable RF delay element based on a time-interleaved multistage switched-capacitor (TIMS-SC) approach. The proposed approach enables hundreds of ns of broadband RF delay by employing sample time expansion in multiple stages of switched-capacitor storage elements. The delay element was implemented in a 45 nm SOI CMOS process and achieves a 2.55–448.6 ns programmable delay range with < 0.12% delay variation across 1.8 GHz of bandwidth at maximum delay, 2.42 ns programmable delay steps, and 330 ns/mm 2 area efficiency. Through the proposed approach, the device shows minimal delay change across a −40 °C to 85 °C temperature range and < 0.25 dB gain variation across delay settings. The device achieves 26 dB gain, 7.4 dB noise figure, and consumes 74 mW from a 1 V supply with an active area of 1.36 mm 2 .