122GHz  Equipment
The basic system is shown on the left during garden testing. It comprises two LO's in the diecast boxes and two RF head units coupled to a pair of Nurad 30cm dish antennas fed with horn feeds.  The Rx head is  on the right and the Tx head on the left.
This photo on the left shows the receive side of the system. Its very similar to the transmit side, with a similar LO. The X2 stage and a X5 stage, using an anti-parallel pair of diodes in the receive mixer whose output is coupled to a  144MHz transceiver via  a preamp.
The system is almost identical to the 134GHz system described elsewhere.  It has seperate Rx & Tx modules and uses a dual dish antenna system shown.  Operational mode is CW by keying a X4 multiplier stage.
The head unit of the Tx system is shown on the right. It is driven by an LO in one of the diecast boxes shown above and comprises an LMX2541 synth chip running at ~3Ghz. The synth. chip gets its reference from a 10MHz double ovened Morion surplus OCXO.The stabilty of the system working into the receiver shown below is excellent, signals after inital warm up, remaining in the pass-band for many hours. The output from the chip is then applied to a X4 multiplier which produces an output at  ~12Ghz.  This is then applied to a X2 and a ~150mW 24GHz amplifier bolted to a heatsink The 24GHz signal drives an anti-parallel diode multiplier in the ally box to produce a X5 signal
If you want  to see what else is going on in the millimeter field in the UK why not visit these sites too?
This photo on the right shows the receive side system LO, comprising
the 10MHz reference, LMX synth. module and the X4 GaAs fet multiplier in the tinplate box.

Click here for a quick look at a garden test of the kit in lash up state.

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