1. Introduction of quartz crystal filter
Quartz crystal filters are mainly composed of specially designed quartz resonators. Because quartz resonators have high Q values, generally tens of thousands to hundreds of thousands, the filters made of quartz crystal filters have the characteristics of low ion loss, good temperature stability, high reliability, high stopband attenuation, small rectangular coefficient and so on. Quartz crystal filters have been widely used in radio, television, communications, navigation, remote control and telemetry, aerospace and other electronic instruments and equipment. They play a role in stabilizing the signal source frequency and ing the signal source frequency, effectively preventing interference.
Our company's filters can be divided into discrete filter and single chip filter according to the internal structure, the frequency range is 1.4M-130M, the bandwidth is 300 Hz-100 kHz, stopband attenuation is 20 dB-90 dB, 60 dB rectangular coefficient is 1.5-5, customers can choose according to needs.
2. Terminology commonly used in quartz crystal filters
1) nominal frequency: the nominal value of the center frequency.
2) Passband width: The frequency interval between two cut-off frequencies of a passband is called passband width, or bandwidth for short.
3) band fluctuation: the maximum difference between peak and trough attenuation in passband.
4) stopband width: the frequency interval between the two cut-off frequencies of stopband is called stopband width.
5) ion loss: the attenuating value of the filter before and after the ion of the filter.
6) termination impedance: the equivalent impedance value of the signal source or load to the filter.
7) Group delay: refers to the time required for signal filter, numerically the reciprocal of the diagonal frequency of the transmission phase function.
3, product ordering and use matters needing attention
1) instructions for ordering products
(a) Product production cycle: Routine product production cycle is about 2-6 weeks, and special product production cycle is formulated and implemented by mutual agreement;
B) Users need to appropriate technical parameters according to the sea creator electronics, such as nominal frequency, bandwidth, input and output impedance, shape size, frequency deviation, ion loss, passband fluctuation, bandwidth, stopband attenuation, etc.
2) matters needing attention in product use
A) a good impedance matching must be achieved according to the design requirements.
B) attention should be paid to putting light to light and avoiding the failure of products caused by high falling or collision.
C) avoid using quartz crystal filter around the strong magnetic field, so as not to affect the performance of the filter.
D) Avoiding the damage and rupture of the insulator caused by the overload bending and stretching of the input and output pins of the filter;
(e) The product should be stored in a warehouse with an ambient temperature of - 10 ~40 C, a relative humidity of not more than 80%, and no acid, alkaline or other harmful gases in the surrounding environment.
4. Measuring filter device