Portland State University. Department of Electrical and Computer Engineering
Date of Publication
Master of Science (M.S.) in Electrical and Computer Engineering
Electrical and Computer Engineering
Frequency multipliers -- Research, Bipolar transistors
1 online resource (ix, 93 pages)
The function of a frequency multiplier is verbatim -- a frequency multiplier is a circuit that takes a signal of particular frequency at the input and produces harmonic multiples of the input signal's frequency at the output. Their use is widespread throughout history, primarily in the application of frequency synthesis. When implemented as a part of a large system, a chain of multipliers can be used to synthesize multiple reference signals from a single high-performance reference oscillator.
Frequency multiplier designs use a variety of nonlinear devices and topologies to achieve excitation of harmonics. This thesis will focus on the design and analysis of single ended bipolar junction transistor frequency multipliers. This topology serves as a relatively simple design that lends itself to analysis of device parasitics and nonlinearities. In addition, design is done in the Very High Frequency (VHF) band of 30-300 MHz to allow for design and measurement freedoms. However, the design methodologies and theory can be frequency scaled as needed.
The parasitics and nonlinearities of frequency multipliers are well explored on the output side of circuit design, but literature is lacking in analysis of the drive network. In order to explore device nonlinearities on the drive side of the circuit, this thesis implements novel nonlinear reflectometry systems in both simulations and real-world testing. The simulation nonlinear reflectometry consists of intelligently configured voltage sources, whereas directional couplers allow for real world nonlinear reflectometry measurements. These measurements allow for harmonically rich reflected waveforms to be accurately measured, allowing for waveform engineering to be performed at the drive network. Further, nonlinear reflectometry measurements can be used to explain how load- and source-pull obtained drive and load terminations are able to achieve performance increases.
Schaeffer, Daniel Dale, "Very High Frequency Bipolar Junction Transistor Frequency Multiplier Drive Network Design and Analysis" (2019). Dissertations and Theses. Paper 5031.