A Beam-Steerable Wideband Reflectarray Antenna for C-Band High-Power Microwave Application

A beam-steerable wideband reflectarray antenna (WRA) for
$C$
-band high-power microwave (HPM) application is presented in this paper. The
$C$
-band WRA comprises a multimode conical horn antenna with high power handling capacity (PHC),
$25\times25$
special designed antenna elements, a metal frame and a dielectric plate used as a radome. In our previous work, it has been verified that a wideband prototype using this antenna element has a relative bandwidth of 50% (3.3-5.5 GHz) and its beam scanning range reaches ±60° in low power experiments. In this paper, combined with the equivalent circuit model, the wideband and high PHC property of the WRA element is further explained. To demonstrate the excellent performance of the proposed element in HPM applications, we combined the
$C$
-band WRA (which was redesigned from the previous wideband prototype) with a well-designed narrowband HPM source operating at 4.3 GHz, and constructed a matching HPM experimental platform. The
$C$
-band WRA works at 4.1-4.5 GHz, and the results of low power experiments indicate that it can maintain good performance during beam scanning. Its sidelobe level and cross-polarization level are always less than −15 dB and −22 dB, respectively, while its maximum aperture efficiency reached 68.99% (the corresponding antenna gain is 28.07 dB at 4.3 GHz). On the other hand, the PHC of the WRA element reaches 3.82 GW/
$\text{m}^{2}$
and the
$C$
-band WRA reaches 1.24 GW in simulation. HPM verification experiments have been carried out, and the experimental results show that the PHC of the fabricated prototype exceeded the expectation, which proves that the WRA has broad application prospects in HPM fields.