Home // International Journal On Advances in Telecommunications, volume 11, numbers 3 and 4, 2018 // View article

Design of On-Chip GaN Transmitter for Wireless Communication

Authors:
Rajinikanth Yella
Krishna Pande
Ke Horng Chen
Edward Chang

Keywords: Yagi antenna; Filter; Mixer; Power amplifier; 5G.

Abstract:
5G standard is targeting much higher data rates as compared to existing wireless technologies to accommodate the ever-increasing demand for faster wireless applications. A transmitter is required to implement a 5G system. In this paper, we are presenting a 28 GHz novel monolithic transmitter architecture on GaN substrate that offers size, weight, area, power, and cost advantages. The transmitter contains a Yagi antenna, which consists of three directors, two drivers, a strip line feed, a substrate, and a ground plane. Optimization is obtained by modifying components design parameters. According to simulation results, the designed Yagi antenna has a compact size, and low loss at the selected frequency of 28 GHz. At this frequency, its return loss, gain, and beam width are - 38 dB, 8.69 dB, and 57.2 degrees, respectively. The second component in the monolithic chain is a bandpass filter, which offers enhanced selectivity and stopband suppression on GaN substrate. The Bandpass filter has a minimum insertion loss of 0.6 dB at 28 GHz. The rejection level is higher than 10 dB in the stop band. Further, a collaborative simulation of 28 GHz mixer for upconversion with CLASS-E power amplifier with the integrated octature structure to achieve robust load insensitivity is presented. In this paper, to design high-efficiency PA, we implemented harmonic load pull at both the input and output of the active device to obtain optimum impedances at fundamental and second-harmonic frequencies. After an iterative process, the optimum input and output impedances are obtained. In addition, we also implemented a cascaded octature power cell structure. The proposed balanced PA achieves a saturated output power of 13.5 dBm and a maximum Power Added Efficiency of 55 %. It consumes 210 mW power. Each power cell is based on class-E. The circuit is implemented using GaN HEMT transistor taking an advantage of its high frequency and high power performance. The presented transmitter configuration is designed at 28 GHz for 5G Application on a GaN substrate with a thickness of 0.8 mm, a permittivity of 9.7, and loss tangent of 0.025.

Pages: 125 to 134

Copyright: Copyright (c) to authors, 2018. Used with permission.

Publication date: December 30, 2018

Published in: journal

ISSN: 1942-2601