Frequency drift

About: Frequency drift is a research topic. Over the lifetime, 5054 publications have been published within this topic receiving 56191 citations. The topic is also known as: chirp rate.

A band-switched integrated voltage controlled oscillator

Abstract: The source to drain capacitance of a FET device is used by connecting the source and drain together electrically so as to form a two terminal capacitive device which may be switched into and out of a parallel resonant circuit. Thus, sets of FET devices with their sources and drains connected together are employed in a circuit which produces an output voltage signal at a frequency which is tunable within a plurality of different individual bands. The resultant voltage controlled oscillator is particularly useful in cellular telephone and related wireless systems and/or in any other situation where integrated high frequency voltage control oscillator circuits are desired.

Transmitter for a radio control device

Abstract: A radio control device includes a transmitter, in which a crystal type high frequency module equipped with a high frequency circuit corresponding to a frequency band of a carrier and a PLL high frequency module equipped with the high frequency circuit and a PLL circuit for controlling a frequency of the carrier depending on a phase difference between the carrier and a reference signal of oscillator are detachably mounted. Such construction permits the crystal type high frequency module and PLL high frequency module to be selectively used as desired and transmission data to be output by means of the carrier of a desired frequency set depending on the high frequency module. Also, the radio control device includes a receiver which employs a frequency synthesizer system in which a PLL, circuit for controlling an oscillation frequency depending on a phase difference between a reference signal and the oscillation frequency is used and includes a frequency selecting means for selecting a required frequency from a plurality of predetermined frequency data and a frequency setting means for fixedly setting a receive frequency on the frequency selected by the frequency selecting means when a power supply is turned on.

Method and apparatus for characterizing and adjusting a crystal oscillator for use in a spread spectrum, frequency hopping transceiver

Abstract: An economical, compact frequency hopping spread spectrum wireless data telemetry transceiver is adapted to establish and maintain communication links at 2.4 GHZ. The wireless transceiver includes RF and computer control components in a compact package approximately the size of a deck of cards and is adapted to be built into original equipment manufacturer (OEM) products to support a wide range of wireless data telemetry applications. The transceiver includes an inexpensive VCO which is controlled by novel method including steps to characterize and adjust the frequency output of the crystal. As ambient temperature around a quartz crystal varies, the resonant frequency of the crystal varies, in different ways, depending on the method used to cut the crystal from a quartz blank. Employing a quartz crystal in an oscillator circuit to generate a reference frequency subjects the oscillator to the same frequency variations over temperature as the quartz crystal. In accordance with the present invention, a temperature sensor constantly outputs a signal proportional to the temperature of the crystal in the oscillator. A micro-controller initiates a conversion via the analog to digital converter (ADC) and the micro-controller then uses the ADC output signal to look up an adjustment number in a pre-programmed lookup table; the adjustment number is input to the digital to analog converter, which then performs a conversion to output a DC voltage to the VCO, adjusting the frequency of the oscillator to the desired reference frequency, thus effectively providing an open loop VCO control system.

High-Stability Bridge-Balancing Oscillator

Abstract: A crystal-controlled frequency standard having a frequency stability of a few parts in 1010 per day is described. The oscillator employs a 1-megacycle GT-cut crystal unit in a high-sensitivity bridge-balancing frequency-correction system. The crystal serves both as the resonant element for the oscilaltor and for a bridge whose unbalance is an indication of departure of the oscillator frequency from the crystal series resonance. The unbalance, greatly amplified, is used to AFC the oscillator.

High frequency power supply device and high frequency power supplying method

Abstract: The present invention provides a high frequency power supply device and a high frequency power supplying method, which can control and supply high frequency power effective on generation of plasmas in a short time with a high precision. The device at least includes a first high frequency power supply block (11), which supplies a plasma processing chamber (5) with a high frequency power at a first frequency f1, and a second high frequency power supply block (71), which supplies the plasma processing chamber with a high frequency power at a second frequency f2 (f1>f2). The first high frequency power supply block (11) includes: a first high frequency oscillating block (16), which excites the high frequency power at the first frequency and has a variable frequency; a first power amplification block (15), which receives an output of the first high frequency oscillating block and amplifies the power thereof; a heterodyne detection block (13), which performs heterodyne detection of a reflected wave; and a first control block (14), which receives a signal after detection at the heterodyne detection block and a traveling wave signal, and controls an oscillating frequency of the first high frequency oscillating block and an output of the first power amplification block.