Temperature and frequency equalizer
AssigneeSmith Interconnect Microwave Components, Inc.
InventorsNelson Roldan, Gene Perschnick, Robert Blacka, Alen Fejzuli
Life of this patent
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Abstract
The present invention is an absorptive-type cable temperature and frequency equalizer that offsets changes in the gain of the other circuit components cables with increases in temperature and/or frequency. The equalizer comprises a temperature variable filter network having component values and a temperature coefficient of resistance that vary over temperature and frequency to produce a desired response. The temperature and frequency equalizer has at least one thick film thermistor connected in series with a quarter wavelength transmission line. The thermistor absorbs forward and reflected signals at lower frequencies.
Claims8
An equalizer comprising:
- a transmission line and ground, and at least one shunt element connected between the transmission line and ground and comprising a thermistor and a quarter wavelength transmission line connected in series, the thermistor having a temperature coefficient of resistance such that the equalizer provides an attenuation that has a substantially constant slope with increasing frequency.
In combination, a cable equalizer and a coaxial cable having a center conductor and a grounding sheath, the cable equalizer comprising,
- a transmission line connected to the center conductor,
- a ground connected to the grounding sheath, and
- at least one shunt element connected between the transmission line and ground and comprising a thermistor and a quarter wavelength transmission line connected in series, the thermistor having a temperature coefficient of resistance such that when the equalizer is connected to a coaxial cable, the coaxial cable has a substantially constant insertion loss at microwave frequencies in excess of about 3 GHz.
Dependencies are inferred from the claim text.