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A tutorial paper on active frequency multiplier design is presented. Rough calculations for a x 2 multiplier using classical theory are developed and used as a starting point for implementation with nonlinear computer-aided design (CAD) software. The power of the nonlinear CAD software for visualizing and understanding concepts important to frequency multiplier design, and also for optimization of critical design parameters is demonstrated through realistic example. Important design considerations for higher order multipliers are discussed, including design of output termination circuitry for a x 4 multiplier at 28 GHz. Index Terms--Active multiplier, computer-aided design (CAD) software, FET multiplier, frequency multiplier, harmonic balance (HB), harmonic terminations, high-order multiplier, nonlinear, optimization, tutorial.

A phase-locked-loop (PLL)-based architecture is proposed for direct generation of frequency stable, high-power Gaussian minimum shift keying (GMSK) and other continuous phase modulations at microwave and millimeter-wave frequencies. A continuous phase frequency shift-keyed (CPFSK) signal with a modulation index of 0.5 is produced at the desired output frequency using a full 360 [degrees] linear continuous phase modulator that is controlled by the integrated baseband information signal. This modulated signal is used as the reference signal for a phase-locked high-power voltage-controlled oscillator. The PLL facilitates reference signal frequency tracking and provides Gaussian spectral shaping to the modulated output signal. PLL imperfections and their effect on the modulated output signal are considered, and simulation results are presented.

Compact reactive lumped-element circuits fabricated using a single thick metal-layer deep X-ray lithography process are presented. Vertically oriented capacitive features are combined with inductive features in > 0.25-mm-thick metal layers to realize lumped-element filter and coupler microstructures operating at up to 12 GHz. Measurements for separate thick metal reactive structures are also presented, including variable capacitors and single-turn square loop inductors. Devices feature impressive vertical structure, including a 77:1 aspect ratio, 1.3-\mum-wide cantilever gap structure in 100-\mum-thick photoresist. A 0.6-pF capacitor has Q-factors of 95 at 5.6 GHz and 214 at 3.5 GHz, and a structurally compatible 1.2-nH loop inductor has a Q-factor of 47 at 6.8 GHz and a self-resonant frequency of 18.8 GHz. Together, these types of devices could form the building blocks for various integrated reactive lumped-element-based circuits. [ABSTRACT FROM PUBLISHER]

This paper introduces a micromachined thick single-metal-layer high aspect-ratio coplanar waveguide (CPW) wideband bandpass filter with compact unit cells based on the electromagnetic bandgap (EBG) concept. The filter is miniaturized as a result of using the EBG concept in design, and also by realizing high aspect-ratio structures with polymer-based deep X-ray lithography fabrication. Cascaded unit cells in the EBG model consist of capacitive and inductive parallel periodically loaded transmission lines, which determine the filter bandwidth. Compact unit cells are realized by using high aspect-ratio CPW stepped-impedance resonators. The main advantage of this approach is that the high aspect-ratio CPW structures make short unit cells practically realizable, resulting in a compact filter structure. A bandpass filter with 47% bandwidth is designed and fabricated using deep X-ray lithography, and the performance and physical size is compared to a conventional quarter-wave- length-based admittance inverter filter. [ABSTRACT FROM AUTHOR]

A finite element (FE) model is developed for investigating effects of metal electrode mass loading in longitudinal leaky surface acoustic wave (SAW) resonators on YZ-LiNbO3. Variation of resonator admittance with electrode height and electrode metallization ratio is observed. FE modeling is promising for the prediction and optimization of LLSAW performance, especially sensitive to electrode mass loading effects. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 390–395, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24042 [ABSTRACT FROM AUTHOR]

A new circular waveguide loaded with two T-shaped septa and a new triple ridge loaded trough rectangular waveguide are proposed and theoretically analyzed using the Finite Element Method. Numerical results are presented demonstrating that these structures offer a significant increase in both fundamental mode cutoff wavelength and bandwidth when compared to various unloaded and loaded waveguides. © 2002 Wiley Periodicals, Inc. Int J RF and Microwave CAE 12: 190–197, 2002. [ABSTRACT FROM AUTHOR]

Metal embedded grid artificial dielectric resonator antennas (GDRAs) fed by different coplanar waveguide (CPW) feeding techniques at mm‐wave frequencies are investigated in detail. GDRAs involve embedding tall nickel metal inclusions in polymethyl‐methacrylate (PMMA) using deep X‐ray lithography and electroforming, which dramatically increases the effective permittivity of the polymer up to 5‐6 times and results in miniaturized antenna structures operating at millimeter‐wave frequencies. The options for different coplanar waveguide (CPW) feeding at 22.6‐26.6 GHz and 26.6‐29.3 GHz are studied by applying a thin 300 μm PMMA layer between the feed layer and metal inclusions of the GDRA to avoid short‐circuiting the underneath feed line structures. In addition, this results in a GDRA structure that improves the impedance bandwidth up to 16.26%, while providing a maximum realized gain of 7.2 dBi across the frequency band with excellent broadband patterns and −18 dB cross‐polarization levels. [ABSTRACT FROM AUTHOR]