Abstract: The invention relates to a self monitoring/calibrating phased array radar in which the operating path for transmission and the operating path for reception may be monitored/calibrated by the addition of a corporate calibration network coupled at the plural end to the antenna elements and at the singular end to the exciter/receiver, and switching means to selectively route the monitoring/calibrating signal derived from the exciter in a transmit path to calibration path sequence or in a calibration path to receive path sequence.In one embodiment of the invention, a phase shifter common to transmit and receive paths is adjustable in increments under active logical control for calibration, while power and gain performance is monitored but not actively controlled. A novel T/R sub-assembly houses the operating electronics for four antenna elements in the form of four T/R modules with a one to four divider network in the transmit/receive path and in the calibration path.

Abstract: A protective shield for an electrically steered, high performance C Band antenna array is disclosed. The shield is of a multi-layer construction in which a sandwich is formed between two fiberglass layers and a central foam core to minimize electrical reflections; and in which an additional foam layer is provided for structural support and to minimize changes in mutual coupling, installed between the sandwich and planarly disposed dipoles of the array. In addition, a teflon layer is applied to the outer layer of the sandwich and coated with fumed SiO.sub.2. The hydrophobic properties of the teflon-fumed SiO.sub.2 combination minimizes the effects of rain on antenna performance.