Ku-밴드 위성 수신기용 FET 저항성 믹서 설계

Abstract

본 논문에서는 주파수 변환을 얻기 위해 GaAs MESFET의 선형채널저항을 이용하는 FET 저항성 믹서를 설계하였다. 이 믹서는 설계가 쉽고, 저잡음이며, 상호변조왜곡을 줄일수 있으므로 저잡음 수신기에 적용할 수 있다.

본 설계에 필요한 주파수 규격은 RF 중심주파수 12.5GHz, LO 주파수 11GHz, IF 1.5GHz, 그리고 RF 통과대역은 1GHz이다.

본 설계에서는 범용 GaAs MESFET를 사용하여 유전율 2.48인 기판에 적합하도록 설계하여 시뮬레이션을 수행하였다. 각 포트의 여파기들은 개별적으로 설계한 후 최적화 하여 결합하였다.

본 논문에서 설계된 믹서는 통과대역에서의 변환손실 약 6dB, 잡음지수 약 4dB, 동적영역 9dBm 정도의 결과를 가짐을 시뮬레이션을 통해 확인되었다.

기존의 X-밴드에서 설계된 게이트 믹서와 비교한 결과 동적영역에서 4dBm, 잡음지수에서 2.7dB 개선되었다. 그러나, 변환이득/손실면에서는 12dB의 감쇠가 있음이 확인되었다.

In this paper, FET resistive mixer was designed, which uses the linear channel resistance of a GaAs MESFET to achieve frequency mixing. This mixer is entirely for use in low noise receivers, because it can be designed easily, has a low noise, and reduce intermodulation distortion.

Required frequency specifications of this design are RF center frequency 12.5GHz, LO frequency 11GHz, IF 1.5GHz, and RF passband 1GHz.

In this design, it is designed properly for substrate that has dielectric constant 2.48 with using general purpose GaAs MESFET and simulated. Each port filters was designed and optimized individually before the mixer was assembled.

Designed mixer of this paper had the results that conversion loss is about 6dB in its passband, noise figure is about 4dB, and dynamic range is about 9dBm through simulation.

Result of comparison between previous designed gate mixer in X-band and this mixer, it is improved 4dBm in dynamic range, 2.7dBm in noise figure but is reduced 12dB in conversion gain/loss.

In this paper, FET resistive mixer was designed, which uses the linear channel resistance of a GaAs MESFET to achieve frequency mixing. This mixer is entirely for use in low noise receivers, because it can be designed easily, has a low noise, and reduce intermodulation distortion.

Required frequency specifications of this design are RF center frequency 12.5GHz, LO frequency 11GHz, IF 1.5GHz, and RF passband 1GHz.

In this design, it is designed properly for substrate that has dielectric constant 2.48 with using general purpose GaAs MESFET and simulated. Each port filters was designed and optimized individually before the mixer was assembled.

Designed mixer of this paper had the results that conversion loss is about 6dB in its passband, noise figure is about 4dB, and dynamic range is about 9dBm through simulation.

Result of comparison between previous designed gate mixer in X-band and this mixer, it is improved 4dBm in dynamic range, 2.7dBm in noise figure but is reduced 12dB in conversion gain/loss.