这个是国外OZ2CPU发表在TEST&MEASUREMENT上的电路,电路制作很实用,是业余爱好者射频测量的好工具,以前有空闲时,动了心思,DIY了一个。MCU是PIC16F876,测量IC是ADI的AD8307。仪器很灵敏,可以外置衰减器,通过LCD的菜单选择。
Specifications
Frequency coverage: 1 kHz to 500 MHz (calibrated)
1 kHz to 1000 MHz (uncalibrated, for
relative power measurements only)
Nominal input impedance: 50 Ω
Input power range: –60 dBm to +30 dBm
(1 nanowatt to 1 watt).
Input power range using 50-dB attenuator: up to 100 kwatts.
Dynamic range: 90 dB with good RF shielded case.
Resolution: 0.1 dBm (1 dBm on bar-graph)
Input return loss: @300kHz: –35dB
@100MHz: –27dB
@500MHz: –25dB
Input SWR: @ 300kHz: 1.036
@100MHz: 1.094
@500MHz: 1.12
Accuracy before calibration: ±1 dB from 1 MHz to 450 MHz.
After calibration: ±0.2 dB at each calibrated frequency.
DC Voltage Measurement: 0 to 20 volts.
DC Voltage Resolution: 20 mV
DC Voltage accuracy after calibration: ±20 mV
Power supply: 9 to 20 VDC
Current consumption: with no LCD light: 30 mA;
with normal LCD light:120 mA.