Design of the Broadband Amplifiers and the Switches Using Lumped Elements
Date Issued
2007
Date
2007
Author(s)
Yu, Wen-Ying
DOI
zh-TW
Abstract
With the rapid progress of wireless communication in recent years, it has received great attention from both the industry and the academic circle. As new products applying the technology are developed, applications utilizing frequency band below 6 GHz can be widely seen in our daily life. Because the amount of data transmission and processing speed increase, wide band will definitely become a trend in wireless communication in the future.
This thesis presents a systematic design approach to realize a broadband amplifier and switch in a conventional transmitter front-end using lumped elements. The first part treats the design of low noise amplifier and cascaded single-stage distributed amplifiers. We have implemented a 2GHz low noise amplifier at fisrt, which uses Avago ATF-33143 pHEMT operating with 4V supply on FR-4 printed circuit board. The architecture of this circuit is a 2-stages amplifier using lossy match. Measurement results reveal that the amplifier exhibits a small signal gain of about 21dB with input/output return loss of 10 dB. The 1-dB compression point（P1dB）is about 22dBm, power added efficiency is about 39%, noise figure is 1.97 dB.
Using traveling-wave theory, this amplifier has the characteristic of wide operation bandwidth. We implemented two circuits. One of them is a 1GHz-5GHz broadband amplifier, which uses NEC NE32584C hetero-junction FETs operating with 2V supply on FR-4 printed circuit board.
The architecture of this circuit is a 3-stages cascaded single-stage distributed amplifier (CSSDA) using microstrip line. Measurement results reveal that the amplifier exhibits a small signal gain of about 25±3dB with input/output return loss of 10dB. The 1-dB compression point（P1dB）is about 11.5dBm, noise figure is about 8dB.
The other is a 1GHz-6GHz broadband amplifier, which also uses NEC NE32584C hetero-junction FETs operating with 2V supply on FR-4 printed circuit board. The architecture of this circuit is a 3-stages cascaded single-stage distributed amplifier (CSSDA) using coplanar waveguide. Measurement results reveal that the amplifier exhibits a small signal gain of about 20±3dB with input/output return loss of 10dB, stability factor of more than 98. The 1-dB compression point（P1dB）is about 11.5dBm, , noise figure is about 7.75dB.
The second part of the thesis involves the design of single-pole double-throw（SPDT） traveling-wave switch, also implemented on FR-4 printed circuit board using lumped discrete components. The operating frequency of this switch is from 0.1GHz to 4.8GHz, using 0V and -3V switch supply voltage. The input and output return losses are better then 9dB and 7.5dB, respectively, while output 1-dB compression point（P1dB）is about 15dBm. On-state and off-state of the switch can be differentiated unambiguously. Advantages of circuits are low cost and easy implementation.
Subjects
集總
寬頻
放大器
切換器
broadband
amplifier
switch
lump
Type
thesis
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