• 한국전자파학회지:전자파기술
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• 제11권4호
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• pp.39-52
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• 2000

A design of 2 stage S-DLVA(successive detector log video amplifier) was studied to detect wide dynamic radar pulse ranging from -70 ㏈m to 0㏈m. A basic design idea was focused on the linear detection in logarithmic scale of wide dynamic range radar pulses from nosie-like weak power of -70 ㏈m to relatively high power 0 ㏈m. It is highly formidable, since it requires high speed detection less than 10 nsec over the operating frequency ranges from 6 to 18 ㎓. A limiter diode, a tunnel diode and an L17-C were used as a protecting device, a detector diode and a log video amplifier in companion as a single stage detector to give voltage output proportional to the input power of about 35 ㏈ dynamic range. A protype of 2-stage DLVA having one more single stage detector was fabricated with a 32 ㏈ low noise amplifier and a 3 ㏈ hybrid coupler to provide total 70 ㏈ dynamic range detection. The logging characteristics were measured to have log slope of 25m.V/㏈ against 70 ㏈ logging range from -55 ㏈m to +15 ㏈m, the log linearity of within +/- 1.5 ㏈, and tangential sensitivity was at -63 ㏈m. The pulse dynamics of rise time and recovery time were measured as 50 nsec and 1.2 $\mu$sec, respectively. The reason might be due to the parasitic capacitances of packaged limiter, tunnel diode, and L17-C.

• 한국전자파학회논문지
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• 제22권6호
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• pp.641-647
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• 2011

본 논문은 0.5~2.0 GHz에서 -70~0 dBm의 동적 범위를 갖는 로그 비디오 증폭기(Successive Detecting Log Video Amplifier, 이하 SDLVA)를 설계 및 제작하였다. 제작된 SDLVA는 5단의 증폭기를 이용한 고주파 출력부, 2단의 로그검파기 그리고 선형성 개선을 위하여 클램핑 연산증폭기를 이용한 가산 회로로 구현하였다. 제작된 SDLVA의 측정 결과는 73 dB 이상의 소신호 이득과 10.1~12.2 dBm의 고주파 포화 출력 특성을 갖는다. 그리고 -70~0 dBm 입력 시 25 mV/ dB${\pm}$1.0 mV의 기울기를 갖고 ${\pm}$1.5 dB 이하의 선형 특성을 갖는 비디오 신호를 출력한다.