Samsung Electro-mechanics Co., Ltd.

Won Jin Baek

Sung Tae Kim

Hyun Hwan Yoo

Jung Woo Sung

Moon Sun Kim

Jeong Ki Choi

Hyung Joon Kim

Young Jin Lee

Yoo Sam Na

Seung Min Oh

Hyo Seok Kwon

Jin Taek Lee

Mu Seon Woo

Byung Sung Kim

A filter comprises a series unit, and a shunt unit disposed between the series unit and a ground. The shunt unit includes resonators that are selectively operated, and each of the shunt resonators includes a film bulk acoustic resonator.

Variable frequency filter

A filter module includes filters. Each of the filters is configured to control communications bands having overlapping bandwidths each with the other. Each of the communications bands, allocated to any one of the filters, has a different limit frequency from the other.

Filter module and front-end module including the same

A derivative superposition circuit for linearization includes a first active element that is provided with first to third terminals and in which the magnitude and direction of current flowing from the second terminal to the third terminal changes on the basis of the magnitude of a voltage applied between the first and second terminals; and a second active element that is provided with first to third terminals and has complementary characteristics with the first active element. The first terminals of the first and second active elements are connected to each other so that a predetermined operational bias voltage is maintained by first and second power supplies through a first impedance, and are connected to an input end through a second impedance. The third terminals of the first and second active elements are connected to an output end, and the second terminals of the first and second active elements are connected to the second power supply through a third impedance.

Derivative superposition circuit for linearization

The present invention relates to an exponential function generator which is realized with only CMOS element without BJT element, not limited by the physical properties of the element or a square circuit, and not complicated in its configuration, and a variable gain amplifier using the same. The exponential function generator includes a voltage-current converter, 1to ncurve generators for mirroring the current from the voltage-current converter, outputting a current adjusted according to a predetermined ratio, and an output end for outputting the sum of the current from the 1to ncurve generators. The exponential current generator is configured to generate the current exponentially adjusted according to the control voltage.

Exponential function generator and variable gain amplifier using the same

The invention relates to a feedback or feedforward type variable gain wideband amplifier. The variable gain wideband amplifier includes a feedback-type inversion amplifier circuitfor amplifying input Vin, a feedback-type non-inversion amplifier circuitfor amplifying input Vin, a power source circuitfor controlling the gain of the non-inversion amplifier circuitand a load circuitconnected between a junction of output terminals of the inversion and non-inversion amplifier circuitsandand power voltage potential VDD to control the gain of the amplifier circuitsandThe variable gain wideband amplifier of the invention is feedforward type, and outputs signals from the inversion and non-inversion amplifier circuitsandvia a single output terminal in order to attenuate third order intermodulation frequency IMgenerated from the amplifier circuitsandThen, predetermined frequencies fand fincluded in the input signal are amplified.

Variable gain wideband amplifier

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.

Growing community of inventors

Kyungki-do, South Korea

Won Jin Baek