Samsung Electro-mechanics Co., Ltd.

Yun Hee Cho

Yun Hwi Park

Ji Hoon Kim

Chul Soon Park

There is provided a power amplifying device having a linearizer in which a bias circuit has an initial impedance set when initially operated, then the impedance is varied according to a level of an input signal and the input signal is amplified in a broad range from a low level region to a high level region, thereby improving linearity of an output signal. The power amplifying device including: an amplifying unit receiving a bias power source and amplifying an input signal; a bias unit varying the bias power source according to a set impedance to provide to the amplifying unit; and an impedance setting unit setting the impedance of the bias unit in response to a preset control voltage when the bias unit is initially operated and re-setting the impedance of the bias unit according to a level of the input signal of the amplifying unit after initial operation of the bias unit.

Power amplifying device having linearizer

There is provided a multi-layered band pass filter capable of improving a stop characteristic out of a pass band and reducing the entire size of the filter. The multi-layered band pass filter includes a ceramic laminated body having at least first to fifth dielectric layers laminated sequentially therein; first and second resonators having symmetrical patterns of first and second inductors formed on the first dielectric layer, and symmetrical patterns of first and second capacitors formed on the second dielectric layer so that they are at least partially overlapped with the patterns of the first and second inductors; a pattern of first and second load capacitors electrically capacitively coupled respectively to ends of the first and second resonators formed on the third dielectric layer; a pattern of first and second notching capacitors electrically capacitively coupled respectively to the other ends of the first and second resonators formed on the third dielectric layer; and first and second ground planes formed respectively on the fourth and fifth dielectric layers, wherein each of the patterns of the first and second inductors is composed of a low impedance portion formed of wide-width lines and a high impedance portion formed of meander-type narrow-width lines from the low impedance portion.

Growing community of inventors

Gyunggi-do, South Korea

Yun Hee Cho