A single-diode frequency doubler using a feed-forward technique

Abstract

In this paper, a novel single-diode frequency doubler design method is proposed. The output fundamental frequency is suppressed by employing a lambda/2 feed-forward transmission line parallel with a diode instead of using balanced structure with two or more diodes. The deployment of feed-forward line reduces the complexity of matching circuit and the circuit is more compact than doubler circuit without feed-forward line. A single-diode frequency doubler design technique is fully described in detail. The circuit is then fabricated and measured for the performances. The measurement results of 1.2/2.4 GHz frequency doubler agree very well with the simulated performances and exhibit 7.8 dB conversion loss with 170 MHz or 14.12% operating bandwidth.