Design of a Microwave Frequency Tripler with Conversion Gain

Abstract

By utilizing a cross-junction-loaded rectangular hole as a defected ground structure (DGS) at the input side and a simple slotline-based defected ground at the output side, a novel microwave frequency tripler with conversion gain is demonstrated. The cross-junction-loaded hole at the input side acts as a reflector with the capability of providing a suitable reflection for the 3rd harmonic and improving the output power; it also maintains a good pass-band performance at the fundamental frequency f ₀. The slotline-based DGS functions as a frequency selector and diminishes unwanted harmonic components at f ₀, 2f ₀, 4f ₀, and 5f ₀ while only passing the desirable multiplied frequency component (3f ₀). With proper DC bias conditions, results from measurements indicate that the developed tripler achieves an approximate conversion gain of 0.9 dB at 3f ₀ under an optimal input power of 2 dBm.