July 2008 [Components] Planar Resonators Arm Tunable Oscillators Last month, Part 1 of this article introduced novel self-injection- locked compact-coupled-planar-resonator (CCPR) oscillators. Part 2 concludes this article with more details on CCPR technology and some product examples. Edward5 proposed a novel, compact, high-Q multilayer integrable printed helical resonator that offers an optimum ratio of loaded quality factor to unloaded quality factor (QL/Q0 ) for minimum phase noise for a given VCO topology.... June 2008 [Communications] Planar Resonators Arm Tunable Oscillators Communication systems rely on low-phase-noise signal sources such as tunable oscillators or phase-lock-loop (PLL) synthesizers for reliable voice communications and to ensure transmitted data integrity. Challenges still remain in achieving reasonable trade offs in low phase noise, low thermal drift, low power consumption, low cost, and potential for integration in integrated-circuit (IC) processes, however.1-38 With ever- increasing demands... May 2008 [Devices & ICs] Large-Signal Approach Yields Low-Noise VHF/UHF Oscillators Last month, the first half of this article introduced the large-signal approach to oscillator design. This concluding section will offer some VHF/ UHF design examples, including the 144-MHz oscillator first presented last month in Part 1. The component values for the 144-MHz oscillator (C1, C2, C3, C4, and L) can be calculated in the following way. First, the values of capacitors C1 and... April 2008 [Components] Large-Signal Approach Yields Low-Noise VHF/UHF Oscillators Oscillator design for veryhigh- frequency (VHF) and ultra-high-frequency (UHF) applications has been well documented in books and journals. Most early work focused on frequency stability and, to a lesser extent, on efficiency and output signal quality. But with increasing use of advanced modulation formats in communications systems, and the growing need for oscillators with... August 2007 [Components] Technique Trims VCXO Phase Noise Frequency reference standards are essential to achieving frequency accuracy and phase stability in electronic systems. Such sources require the chief characteristics of low phase noise and good frequency stability.1-13 The best oscillator performance can be expensive, however. Fortunately, a patented approach has been developed to design and optimize the performance of voltage-controlled crystal oscillators (VCXOs), even those with relative low quality-factor... April 2006 [Components] Cost-Effective VCOs Replace Power-Hungry YIGs Phase noise is the curse of many a communications system, and one of the key performance parameters that most oscillators strive to minimize. System designers have long recognized the yttrium-iron-garnet (YIG) oscillator for its broadband, low-noise, high-frequency capabilities. But YIG sources are also power hungry and physically large. The mechanical design, with a YIG sphere mounted in the air gap of an electromagnet, is not conducive to integrated-circuit (IC)... June 2004 [Components] Low-Noise VCOs Conquer Wide Bands Bandwidth and phase noise are two of the leading requirements for signal-generating components in modern communications equipment. Voltage-controlled oscillators (VCOs) have been the frequency source of choice for many wired-, wireless-, and... |
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