crystal filter การใช้

• The first IF stage uses a crystal filter with a 12 kHz bandwidth.
• A crystal filter is very often found in the receivers.
• Ceramic filters at 455 kHz can achieve similar bandwidths to crystal filters at 10.7 MHz.
• In modern designs it is common to use quartz crystal filters, especially for narrowband filtering applications.
• The use of a fixed IF stage frequency allows a crystal filter to be used because it has a very precise fixed frequency.
• The best way would be to have a narrow crystal filter at 10 MHz, but even so the ionosphere causes fading and phase shifts.
• The cut of the quartz crystal determines the crystal's vibrating frequencies, such as the common AT cut used for crystal filters designed for radio communications.
• By changing the voltage applied to this crystal filter, it will work as a switching polarising filter, giving different gray scales of the light coming out.
• Another additional difficulty of the crystal interferometer is that the Laue crystals filter most of the incoming radiation, thus requiring a high beam intensity or very long exposure times.
• Using its synthetic quartz crystals, NDK produces crystal-related products such as crystal devices ( e . g . crystal units, crystal oscillators, crystal filters ) and ultrasonic transducers for medical use.
• Berns'alternative system, which he calls multispectral imaging, currently involves taking 30 photographs of a painting through a special liquid crystal filter that is repeatedly adjusted to allow different frequencies of light through.
• The most common use of crystal filters are at frequencies of 9 MHz or 10.7 MHz to provide selectivity in communications receivers, or at higher frequencies as a roofing filter in receivers using up-conversion.
• Cady held more than 50 patents, and was the inventor of the crystal-controlled oscillator, the highly selective narrow-band crystal filter, one of the principal theorists of the ferroelectricity in crystals, and a historian of the science of piezoelectric crystals.