RF Testset

A large part of the radar transmission/reception chain is formed by RF components.

In the LVA antennas of modern (M)SSR and 3D PSR radars RF signals are split and distributed along the different elements of the array antenna. Possible errors in all of these elements can be measured by the RF Testset. The RFT646 is a versatile dual-channel L-band Tx/Rx measuring unit, capable of generating fixed or swept frequency RF test signals in the 900-3500 MHz range.

Most important functions:

  • Vector Network Analysis:
    • LVA column fault finding
    • Measuring the RF parts of the radar chain:
      • Rotary joint: leakage, reflections, loss
      • Low loss cables: VSWR, Loss, Cable damage
      • Monopulse cables: Phase alignment Splitters, couplers, switches, etc...
  • Pulse Vector Voltmeter

A special accessory kit for the RFT646, called the 3D Antenna Scan – 3DS, together with a dedicated VNA scanning software allows to predict antenna far field diagrams or detect defective or degraded transmitter performance of 3D phased array antennas.

Some RASS-S applications using the RFT646 verify the performance of single or multiple channel primary receivers and their connected (3D) antennas. Some radars have an IF output, or perform the beam-forming action using the IF signals. The DID647 serves as a Downconvertor for the IF signal of these radars (typically 10-30Mhz) to be input in the RFT646.

A typical application in RASS-S for the DID647+RFT646 is the VNA (Vector Network Analysis) tool, where the first IF channel (after passing through the DID647) serves as a reference for the second channel. The phase and amplitude of the second channel signal will be measured relative to the first channel. Therefore it is important that the phase and amplitude coherence of signals passing the two channels is maintained through the down-conversion. The DID647 was specially designed to obtain that result.

The standard model DID647 is delivered with a tunable frequency range of 10 to 30MHz. The down-converted output has a frequency range of 0 to 4.7MHz.

Applications for the DID647 include:

  • RFT646 VNA (Vector Network Analyser) for IF output signals
  • IQ alignment of PSR radar receivers with IF
  • Near field measurements (3D Scan)
  • Solar measurements