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Waveguide Packaging of Quasi-Optical Grid Amplifiers


Cheung, Chun Tung (2003) Waveguide Packaging of Quasi-Optical Grid Amplifiers. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/KSGC-3G92.


Quasi-optical amplifiers combining the output powers of hundreds of transistors have demonstrated the capability to deliver more than 10 Watts of power at millimeter wave frequencies. However, these amplifiers are large and expensive to manufacture. In this work, we attempt to find a compact, low-cost approach using metallic waveguide to package a grid amplifier. This thesis details the design and implementation of a grid amplifier packaged in waveguide. Frequency and time-domain simulation methods are used to calculate the field flatness and the small signal gain of the amplifier. Four different active grids packaged in waveguide will be reported. The first grid, operating at Ka-band, is fed with a waveguide and radiates its output into free space. The amplifier chip design was previously measured in free-space. This work demonstrates a small signal gain of 7 dB with output power of 5.5 W at 3-dB compression. The performance is similar to the same grid design measured in free-space. A second Ka-band grid amplifier packaged in waveguide for both input and output gives a small signal gain of 6 dB. The 3-dB compressed output power is 670 mW while the same amplifier measured in free-space gave 1.2 W output power. In order to further verify our active grid and packaging design methods, a V-band single-stage monolithic grid amplifier was designed and fabricated. A transmission grid amplifier and a reflection grid amplifier using this chip were fabricated. Both amplifiers have 2 dB small-signal gain at 58 GHz. In order to increase small-signal gain, a two-stage monolithic grid amplifier was designed and fabricated. A reflection approach was used to package this chip. Measured small-signal gain was 2.7 dB at 82 GHz.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Grid Amplifiers; Quasi-Optical
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Electrical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Rutledge, David B.
Thesis Committee:
  • Rutledge, David B. (chair)
  • Hajimiri, Ali
  • Rosenberg, Jim
  • Vahala, Kerry J.
  • Bridges, William B.
Defense Date:20 March 2003
Non-Caltech Author Email:lawrence (AT)
Record Number:CaltechETD:etd-05192003-161134
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1867
Deposited By: Imported from ETD-db
Deposited On:21 May 2003
Last Modified:03 May 2021 21:30

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