A dual-band antenna matching system and a method for dual-band impedance matching are provided. The method comprises: accepting a frequency-dependent impedance from an antenna; and, selectively supplying a conjugate impedance match for the antenna at either a first and a second communication band, or a third and a fourth communication band. More specifically, the method comprises: tuning a first tuning circuit to a first frequency; and, simultaneously tuning a second tuning circuit to a second frequency. In response, a conjugate match is supplied to the antenna in the first communication band in response to the first frequency. Simultaneously, the antenna is matched in the second communication band in response to the second frequency. When the first tuning circuit is tuned to a third frequency, and the second tuning circuit is tuned to a fourth frequency, then conjugate matches are supplied for the third and fourth communication bands, responsive to the third and fourth frequencies, respectively.

System and method for dual-band antenna matching

A mismatch detector including a directional device adapted to couple signals across the device and a detector coupled to a port on the directional device and configured to measure a reflected power a second detector coupled to a port on the directional device and configured to measure a transmit power. The mismatch detector may be used in wireless communication devices, including, but not limited to mobile wireless devices, base stations, and communication systems.

Systems and methods for controlling output power in a communication device

A family of FE dielectric-tuned antennas and a method for frequency tuning a wireless communications antenna are provided. The method comprises: forming a radiator; forming a dielectric with ferroelectric material proximate to the radiator; applying a voltage to the ferroelectric material; in response to applying the voltage, generating a dielectric constant; and, in response to the dielectric constant, communicating electromagnetic fields at a resonant frequency. Some aspects of the method further comprise: varying the applied voltage; and, modifying the resonant frequency in response to changes in the applied voltage. Modifying the resonant frequency includes forming an antenna with a variable operating frequency responsive to the applied voltage. Alternately stated, forming an antenna with a variable operating frequency includes forming an antenna with a predetermined fixed characteristic impedance, independent of the resonant frequency.

Tunable horn antenna

The present invention provides for low loss tunable matching circuits at rf frequencies. Ferro-electric materials are used to produce low loss tunable capacitors and inductors for use in matching circuits.

Tunable matching circuit

A sub-band antenna matching method and an antenna matching system for selectively matching a communication bandwidth segment impedance have been provided. The method comprises: accepting a frequency-dependent impedance from an antenna; and, selectively supplying a conjugate impedance match for the antenna at a sub-band of a first communication band. In some aspects, the method selectively supplies a conjugate impedance match for the antenna at a sub-band of a second communication band. More specifically, the method comprises: tuning a first tuning circuit to a first frequency; simultaneously tuning a second tuning circuit to a second frequency to match the antenna at a low end of the first communication band. Likewise, the first tuning circuit is tuned to a third frequency and the second tuning circuit is tuned to a fourth frequency to match the antenna at a high end of the first communication band in response to the third and fourth frequencies.

System and method for impedance matching an antenna to sub-bands in a communication band

A temperature compensation circuit (10) for a crystal oscillator module (12) used in a communication device (200). An existing microcontroller (210) of the communication device (200) is used to provide temperature compensating digital data (30) for a crystal oscillator (18). In this way, the crystal oscillator module (12) does not require an on-board memory which substantially cuts costs. The temperature compensation digital data (30) is converted to a temperature compensation signal (22) in a digital-to-analog converter which controls the crystal oscillator frequency. However, typical digital-to-analog converters are driven by voltage regulators which vary over temperature. To solve this problem, the crystal oscillator module (12) includes an on-board voltage regulator (34) which supplies a characterized regulated voltage (36) to the digital-to-analog converter such that the temperature compensation signal (22) from the digital-to-analog converter is inherently corrected for voltage variations in the voltage regulator (34). This improves stability of the output frequency (20) from about 5 ppm to about 2 ppm.

Temperature compensation circuit for a crystal oscillator and associated circuitry

PURPOSE: A temperature compensation circuit for a crystal oscillator module used in a communication device is provided to obtain improved temperature compensated output frequency without an on-board ASIC(application specific intrefrated circuit). CONSTITUTION: A temperature compensation circuit(10) for a crystal oscillator module(12) used in a communication device. An existing microcontroller of the communication device is used to provide temperature compensating digital data(30) for a crystal oscillator(18). In this way, the crystal oscillator module(12) does not require an on-board memory which substantially cuts costs. The temperature compensation digital data(30) is converted to a temperature compensation signal(22) in a digital-to-analog converter which controls the crystal oscillator frequency. However, typical digital-to-analog converters are driven by voltage regulators which vary over temperature. To solve this problem, the crystal oscillator module(12) includes an on-board voltage regulator(34) which supplies a characterized regulated voltage(36) to the digital-to-analog converter such that the temperature compensation signal(22) from the digital-to-analog converter is inherently corrected for voltage variations in the voltage regulator(34). This improves stability of the output frequency(20) from about 5 ppm to about 2 ppm.

Temperature compensation circuit for crystal oscillator

A temperature compensation circuit (10) for a crystal oscillator module (12) used in a communication device (200). An existing microcontroller (210) of the communication device (200) is used to provide temperature compensating digital data (30) for a crystal oscillator (18). In this way, the crystal oscillator module (12) does not require an on-board memory which substantially cuts costs. The temperature compensation digital data (30) is converted to a temperature compensation signal (22) in a digital-to-analog converter which controls the crystal oscillator frequency. However, typical digital-to-analog converters are driven by voltage regulators which vary over temperature. To solve this problem, the crystal oscillator module (12) includes an on-board voltage regulator (34) which supplies a characterized regulated voltage (36) to the digital-to-analog converter such that the temperature compensation signal (22) from the digital-to-analog converter is inherently corrected for voltage variations in the voltage regulator (34). This improves stability of the output frequency (20) from about 5ppm to about 2ppm.

Syed S. Raza

Papers

Temperature compensation circuit for a crystal oscillator and associated circuitry

Temperature compensation circuit for crystal oscillator

Temperature compensation circuit for a crystal oscillator