Design of Resistive Mixers and 60 GHz Channel Measurement

• Main Authors: Chien-Chung Lo, 羅健中
• Other Authors: 黃天偉
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/16731938068003975669

碩士 === 臺灣大學 === 電信工程學研究所 === 98 === The thesis consists of two parts. The first part concerns the study of resistive mixer. Resistive mixers are widely used in mm-wave designs because of their virtually zero power consumption, excellent linearity. We will give a brief introduction of how resistive mixers perform mixing. Based on resistive mixers, there are two mixers designed in this thesis. The first one is a dual quadrature mixer, which is to improve the LO-to-RF isolation. For an up converting mixer, the LO leakage to the input of the power amplifier is fed with the RF signal and transmitted through the antenna. It could cause interference for the system. For a down converting mixer, the LO leakage to the output of the low noise amplifier (LNA) may affect the performance of LNA or even cause oscillations. We also list some other existing topologies of mixer for the enhanced LO-to-RF isolation purpose. The other mixer designed is the ×2 subharmonic resistive mixer. It needs only half the LO frequency as the fundamental mixer does. The advantage of the subharmonic mixer is the reduction of LO leakage into the RF and IF ports. We also apply the drain bias technique to further improve the linearity of the subharmonic resistive mixer. The second part of the thesis is 60 GHz channel measurement. We start with the path loss verification by using horn-to-horn measurement with vertical-to-vertical and horizontal-to-horizontal polarizations. If we know the penetration loss and reflection loss of indoor materials, we can predict how much power is received at the Rx side. We choose the plastic partition, the wooden boards, and the tempered glass for the following measurement. The beamwidth and the gain of the horn antennas are 10 degrees and 22.73 dB. For the penetration loss, we not only measure the normal incident penetration loss but also move the Rx antenna within its beamwidth to see if the materials are homogeneous. For the reflection loss, we measure it from the incident angle 10 degrees to 80 degrees. We make the comparison between v-to-v and h-to-h polarizations for the measurement of the penetration loss and the reflection loss both.