Extraction of second harmonic from an InP based planar Gunn diode using diamond resonator for milli-metric wave frequencies

Mohamed Ismaeel Maricar,Ata Khalid,D.R.S Cumming,C.H Oxley

doi:10.1016/j.sse.2015.12.001

Abstract

Planar Indium Gallium Arsenide (In0.57Ga0.47As) Gunn diode was fabricated on a semi-insulating indium phosphide substrate with on chip matching circuit to enable the extraction of second harmonic in millimeter and terahertz frequencies. The In0.57Ga0.47As planar Gunn diodes were designed with an active length of 4μm, channel width of 120μm and integrated with a novel diamond resonator to suppress the fundamental and extract the second harmonic. The experimental results gave good fundamental suppression and extraction of second harmonic (121.68GHz) with an RF output power of −14.1dBm. This is highest recorded power at the second harmonic from a planar Gunn diode.

Highlights

Gunn diodes were first demonstrated by J.B
This paper presents a method to extract the second harmonic from the planar Gunn diode by using coplanar waveguide (CPW) matching elements and a novel diamond stub resonator [10]
It is interesting to note with this device there was only a small indication of negative resistance when compared with measurements carried out on similar Gallium Arsenide (GaAs) based planar Gunn diodes [13]

Summary

Introduction

Gunn diodes were first demonstrated by J.B. Gunn in 1963 using a GaAs bar structure with electrical contacts on opposite faces [1]. Recent modified devices have achieved RF output powers of À4.5 dBm at a fundamental frequency of 100 GHz [3,4] It was reported the inclusion of pseudomorphically grown In0.53Ga0.47As layer on a GaAs substrate increased the planar Gunn oscillation frequency to 118 GHz [5]. In 2013 Khalid et al [6] designed and tested a In0.53Ga0.47As planar Gunn diode with an active length of 1.3 lm fabricated on an InP substrate and measured a fundamental oscillation frequency of 164 GHz with an RF output power of À10 dBm [6]. The planar Gunn diode can be fabricated as part of a microwave monolithic integrated circuit (MMIC) making the feasibility of including simple two terminal devices as frequency sources.

Device fabrication

Experimental results

Conclusion