Pseudorandom-Noise-Modulated Ultra-Wideband Magnetless Nonreciprocal Transmission Line

Abstract

Nonreciprocal transmission is essential in a wide range of applications due to its unique ability to control the flow of signals or energy in a specific direction without allowing for its reversal. This letter proposes a novel ultra-wideband magnetless transmission line using pseudorandom noise (PN) sequence modulation. By applying the properties of strong autocorrelation for PN sequences, two PN sequences with the same elements but different delays are utilised to achieve synchronised forward transmitting propagation and unsynchronised backward isolating propagation. A pair of double-sideband mixers are applied for the modulation. An experiment is performed to demonstrate the proposed nonreciprocal transmission line. The experimental results show that a ultra-wideband from 0.5 to 3.5 GHz forward propagation and more than 13 dB backward isolation are achieved. The proposed nonreciprocal transmission line is compatible with silicon-based integration.