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A novel antenna with the combination of the shorted-edge patch and the coupling feed is proposed in this letter. This new combination still keeps the good features of patch antenna, such as low cost and easy integration. Moreover, it simultaneously possesses several useful features: low cross polarization, wideband, high gain, and adjustable beamwidth in design. To show the effectiveness, a prototype operating at the central frequency of 12.5 GHz is designed and measured. Good agreement between the simulated and measured results has been obtained. The gain and the cross-polarized level are 11.2 dBi and −40 dB, respectively, and the bandwidth is 35%.

Single-sideband time-modulated phased array (STMPA) provides beam-scanning capability and eliminates some undesired sidebands. To further improve the frequency spectrum, the time modulator of the STMPA with S -step waveform for better eliminating the undesired sidebands and widening the allowable signal bandwidth without aliasing is proposed in this letter. The S -step waveform is realized by digital attenuators in time modulators. Most of sidebands are eliminated and the allowable signal bandwidth becomes 4 S times as wide as that of conventional time-modulated array (TMA). The general expressions of the sideband level (SBL) and the theoretical loss of the time modulator related to the number S of the steps are given. To experimentally verify the feasibility of the proposed design, the time modulator with four-step waveform and the corresponding four-element STMPA are fabricated and measured.

A low-profile differentially fed microstrip patch antenna with broad impedance bandwidth is proposed by incorporating a resonant mode of the slot into TM10 and TM12 modes of the patch resonator. Initially, the shorting pins are symmetrically placed underneath the patch so as to push up the resonant frequency of TM10 mode in proximity to that of TM12 mode ( f 12). After that, the central slot could be employed to excite an additional mode resonating closely to the f 12 by increasing the slot length. Additionally, a pair of small circular disks is introduced below the radiating patch for good impedance matching. Finally, the wideband antenna is fabricated and measured to validate the predicted performance. The results illustrate that the antenna has gained a broad impedance bandwidth of about 55% (1.62–2.85 GHz) with three in-band attenuation poles while maintaining the normal radiation pattern. In particular, a low-profile property with the height of about 0.06 free-space wavelength is achieved.

A new type of digital beamforming (DBF) multibeam antenna array is proposed. In this antenna array, the amplitude and phase distributions on the array aperture are recovered using a single radio frequency (RF) channel through time sequence phase weighting (TSPW). The distributions can then be used to produce multibeams by digital beamforming. A proof-of-concept prototype of an eight-element receiving array in JC-band has been fabricated and tested. The measured results confirm the validity and advantages of the proposed scheme.