Samsung Electro-mechanics Co., Ltd.

Hyo Seok Kwon

Seung Min Oh

Yoo Sam Na

Young Jin Lee

Hyun Hwan Yoo

Won Jin Baek

Ki Won Choi

Jin Taek Lee

Jeong Ki Choi

Gi Won Choi

The present invention relate to a wideband frequency generating apparatus using a frequency dividing method of dividing a frequency signal of a voltage control oscillator to expand a frequency generating range. The apparatus comprises an oscillator unit generating a predetermined frequency signal, a mixer having a first input coupled to the oscillator unit to generate a difference signal by mixing the predetermined frequency signal with a signal inputted to a second input of the mixer, a first switch tuned on/off and coupling the predetermined frequency signal to an output of the mixer, a second switch turned on/off and coupling the output of the mixer to the second input of the mixer to form a feedback loop, a &#xbd; frequency divider dividing the output of the mixer by &#xbd; to generate a divided signal, a third switch tuned on/off and coupling the divided signal of the &#xbd; frequency divider to the second input of the mixer unit, and a control logic unit generating on/off control signals turning on/off the mixer, the first switch, the second switch, the third switch in accordance with a selection of frequency generating ranges.

Device for generating wide tunable frequency using frequency divider

A frequency conversion apparatus having a mixer eliminates phase miss-matching between two intermediate frequency (IF) signals having the same frequency and a 90 degree difference in phase. The frequency conversion apparatus for compensating for phase mismatching of first and second IF signal in response to an RF input signal transmitted through an RF input terminal includes a quadrature signal generator (QSG) outputting first and second oscillating frequency signals having a 90 degre difference in phase, a first mixer mixing the RF input signal with a first resultant frequency signal having a first resultant phase and generated from the first oscillating frequency signal and an inverted signal of the second oscillating frequency signal, and a second mixer mixing the RF signal with a second resultant frequency signal having a second resultant phase and generated from the second oscillating frequency signal and an inverted signal of the first second oscillating frequency signal. The frequency conversion apparatus having a mixer improving a signal-to-noise (SN) ratio and increasing an image-rejection ratio by correcting phase miss-matching.

Mixer and frequency conversion apparatus for improving phase-mismatching

A linear channel select filter for an Intermediate Frequency selector of a satellite broadcasting tuner, linearly changes a desired frequency by adjusting an output current, and includes: a transconductance (GM) current cell controller for determining a control voltage according to a select signal, generating the output current according to an differential input voltage, linearly controlling the output current according to the control voltage, and providing a linearly variable resistance according to the linearly controlled output current, and a capacitor circuit coupled to the GM cell controller to provide a capacitance to generate a cutoff frequency voltage according to the output current and the variable resistance. An occupying area and a size of the filter are reduced.

Linear channel select filter

Disclosed herein is a digital automatic fine tuning method and apparatus, which is capable of detecting a difference between a nominal frequency and an intermediate frequency generated in a tuner using a counter, and applying the counted data of the counter as a fine tuning value for the intermediate frequency without using a decoder by controlling the reset and preset operations of the counter that counts the frequency of the intermediate frequency.

Digital automatic fine tuning method and apparatus

Disclosed is a quadrature signal generator for generating an in-phase signal and a quadrature-phase signal, which is capable of generating a quadrature signal having the same frequency as a differential oscillating frequency, using a feedback control system. The quadrature signal generator includes an oscillator for generating a differential oscillation frequency signal having predetermined differential oscillation frequencies; a feedback type frequency doubler for generating a differential frequency signal having differential frequency components corresponding to differential frequency components of a frequency sum signal obtained by summing the differential oscillation frequency signal received from the oscillator and a differential feedback signal received at the differential feedback terminal; and a frequency divider for dividing the differential frequency signal received at the differential input terminal thereof by 2, thereby generating a quadrature signal consisting of two differential output frequency signals to supply at least one differential output frequency signal of the quadrature signal to the feedback type frequency doubler as the differential feedback signal.

Quadrature signal generator with feedback type frequency doubler

The present invention relates to a variable oscillation frequency resonance circuit and voltage controlled oscillator using the same, which includes an inductance element, frequency varying means, and oscillation band varying means. The oscillation band varying means is provided with one or more capacitance element pairs and one or more differential switching element pairs each being arranged between capacitance elements of each of the capacitance element pairs, with differential switching elements of each of the differential switching element pairs being arranged in parallel with each other, to allow a corresponding capacitance element pair to be connected to the inductance element in response to second control signals.

Growing community of inventors

Kyungki-do, South Korea

Hyo Seok Kwon