D1: Losses in Tx chain
This procedure allows to determine losses in the transmit chain at low power. It helps to identify eventually broken components in the transmit chain (e.g. circulator, antenna switch, cables).
This procedure tests all the elements along the signal path: cables inside the outdoor cabinet, circulator, VSWR coupler, antenna switch and finally the antenna cable. An alternative to this method would be to measure the S21 parameter using an S-parameter analyzer set at the radar frequency.
- Spectrum analyser
- Stop acquisition
- Disconnect the RF signal cable from the input of the amplifier (Media:PictureAmpInputDegreane.png) and connect it to the input of the spectrum analyser
- Configure a one-measurement (vertical beam) wind cycle on PCA (pulse width = 2500 ns)
- Start acquisition
- Measure the peak power with the spectrum analyser (settings: center frequency = 1290 MHz, video bandwidth = 2 MHz)
- Connect the RF signal cable to the circulator input (Media:PictureAmpInputDegreane.png)
- Disconnect the cable from the divider of the vertical antenna and connect it to the spectrum analyser
- Measure the peak power
- Repeat step 3 and 8 for each antenna