For the circuits under consideration as the frequency values of the reference quartz oscillator
were used [f.sub.RO] = 100 MHz for the three values of the output frequency of the VCO of hybrid synthesizer [f.sub.FS] = 500, 2000, and 3500 MHz.
The next obstacle faced by Lyons and his group was to develop a method to automatically adjust the quartz oscillator
frequency until it matched the frequency of the ammonia absorption line.
The master synthesizer generates a sinusoidal signal with the frequency of [[omega].sub.IF] + [[omega].sub.D], where [[omega].sub.D] is the driving frequency and it is set to be close to the resonance frequency of the quartz oscillator
. The outputs from the two synthesizers enter the first multiplier and the driving-frequency signal with the frequency [[omega].sub.D] is produced by the following low-pass filter.
Where a separately bonded resonator is used, package size is comparable to the smallest quartz oscillators
, and the cost is similar if not lower.
Despite these advantages, manufacturers can't afford to take for granted the likelihood that quartz oscillators
will go the way of the vacuum tube--they are a proven technology and have been for the last 50 years.
This remained true in the early days of quartz oscillators
. However, as quartz oscillator
technology continued to improve, it became evident that HF radio was limiting the accuracy of the frequency and time signals being delivered.
In the last decade, micro-electromechanical systems (MEMS) oscillators began replacing quartz oscillators
in many applications, including high-reliability automotive applications .
Frequency's Morion affiliate supplies high-quality, cost effective quartz oscillators
Tokyo, Japan, Nov 17, 2005 - (JCNN) - Epson Toyocom has commercialized its TSU series of high precision pressure measurement sensors with quartz oscillators
, and starts shipment in sample quantities for 400,000 yen ($3,400) per unit from late November.
Frequency's Morion affiliate supplies high-quality, cost-effective quartz oscillators
The early SiTime products will replace quartz oscillators
in fit and function, later the full advantages of the MEMS technology will be brought to bear.