[Guangxi Normal University School Competition] FM FM Receiver

Question B FM FM receiver sensitivity measuring device

1. Task

Design and build an FM receiver sensitivity measurement device.

two,

1.Basic requirements

(1) Design and produce a fixed carrier output device with a frequency of 98MHz and an SMA or Q9 interface output (50 ohm impedance).

(2) The carrier output amplitude is below -20dbm (50 ohm impedance) and needs to be measured with a spectrum analyzer.

2. Play part

(1) Make an FM transmitter with a modulation frequency offset of 75kHz and a frequency range of 88-108MHz;

(2) Ability to manually/numerically control the carrier frequency of the FM transmitter, with the number of frequency points being no less than 4.

(3) Further attenuate the amplitude of the FM signal, the output is below -40dbm, and has a step adjustment function with an accuracy of less than 1DB.

(4) The FM signal has a shutdown function

3. Description:

(1) Reserve a test endpoint at the FM output end (for testing).

(2) The signal emitted by FM is directly connected to the radio with an SMA cable for reception, and the sensitivity of different radios is measured.

Award information: Second Prize in Guangxi Normal University School Competition

Team member information: Huang Yueqing, Meng Yehui, Qin Hongting

Instructor: Su Jiande

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