To radiate power we must have a means of generating it in a controlled way and releasing it into space. To achieve this we have a Transmitter sub-system, whose job is to convert low voltage alternating current into high power microwave energy. It is this microwave energy we send out to the target.
The Goldstone Planetary Radar actually uses an X-band transmitter installed on the 70-m DSS-14 antenna at Goldstone. The Klystrons are installed in the XKR cone. We shall describe here the X-Band sub-system.
The heart of the X-Band transmitter comprises two klystron amplifiers. These are special, indeed "unique", high power vacuum tubes. It is their power we radiate towards the target.
The operation of such a high power continuous wave sub-system requires dedicated people expertise, as well as a watchful array of safety devices and procedures to protect both the operators and the equipment from damage.
The echo signal returning from a distant target is usually very faint. In order to be able to capture it we have to use very sensitive amplifiers which increase the signal level without adding anything else. Such amplifiers are called "Low Noise" because they amplify without contaminating the weak signal level appreciably. For the Radar we use a dual-channel HEMT amplifier. These are the most sensitive of all and are also the type used for tracking and receiving spacecraft signals, which are similarly faint.
The custom signal processing system used to record and display received radar echos.