| notes | "The 9S32 Grill Pan Fire Control Radar System is a multiple-target X-band tracking and guidance radar using a 10,000-element space-fed transmission lens. Above the radar array is an IFF planara array, and below it are three sidelobe canceller antennas, which are mechanically steered to cover the main array sidelobe structure on up to three selected targets.
There are two monopulse feeds on the top of the rotating radar turret. The upper feed is covered by a white, Teflon-like shell and is used when the array is set to 30° tilt for aircraft targets. The lower feed is further forward on the roof of the turret and is in line with the center axis of the array when it is tilted to approximately 45° for TBM intercepts.
The emphasized features of the SA-12 system, including the Grill Pan array, are low RF loss and low cost. The phase shifters are Faraday rotators, having two sections in series, controlled by separate coils, with a total phase of 720°.
In each phase shifter, the first coil is connected in series with coils of other phase shifters in that row and driven by the row command. The second coil is connected in series with coils of the other phase shifters in that column and driven by the corresponding column command. Thus, a 10,000-element array, 100x 100 elements, requires only 100-row drivers and 100 column drivers. There are no electronic components on the phase shifter.
The radar transmits right circular polarization and receives left circular (the predominant target echo polarization), and hence the Faraday rotator uses the same control field for the reception as for transmission.
The control field is changed only when the beam position is changed. During a dwell of several milliseconds, several hundred pulses are transmitted and received." |
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