Compact, tunable large group delay line

Abstract

In this letter, we present a compact, tunable delay line based on left-handed nonlinear transmission line (LH NLTL). The widely tunable range of the large group delay is achieved by controlling a reverse bias voltage of series varactors in the LH NLTL. The proposed tunable delay line can be made in a very compact form since its size is dominated by the cascaded varactors. Our experiment shows that the fabricated prototype exhibits tunable group delay between 1.2 ns and 2.2 ns at afrequency of 1.42 GHz with good return loss. The circuit size is merely 1.6 em in length.

A rectangular-shaped time-delay line inspired by CRLH TL unit cell for UWB operation

“…(2) - (6) show that the structural parameters L R , C R , L L and C L determine β and hence can be used to adjust the time delay of the unit cell given in (1). To increase the operation bandwidth of the time-delay line, we propose to rotate the CRLH TL cell of Fig.…”

“…CRLH TL can be used to design many different microwave components such as phase shifters, antennas and bandpass filters, etc. Recently, time-delay lines based on CRLH TL have been proposed and studied [3][4][5][6]. However, these designs have relatively narrow bandwidths.…”

A circular-shaped time-delay line inspired by CRLH TL unit cell for UWB operation

“…CRLH TL can be used to design many different microwave components such as phase shifters, antennas and bandpass filters, etc. Recently, different design approaches of timedelay lines based on using the CRLH TL have been proposed and studied [3][4][5]. However, these designs share one of the major drawbacks, i.e., the bandwidth is relatively narrow.…”

Design of Group Delay Time Controller Based on a Reflective Parallel Resonator

“…However, the GD variation is very slight and the time delay flatness is in need of improvement. Likewise, the circuit presented in [11] has a low GD tuning range and a narrow operating bandwidth.…”