No abstract

A novel series-fed microstrip patch array antenna for 37/39 GHz beamforming is proposed. To improve the antenna bandwidth, two of the patches are modified with truncated corners in the diagonal direction. This truncation generates two degenerate resonances which result in a flattened frequency response of the input impedance. Then, the recessed microstrip feeds for the other two patches are designed to yield a proper current distribution for radiation while maintaining minimal return loss, wide bandwidth, and low sidelobes. Though the individual patch antenna is elliptically polarized due to the truncated corners, a phased array with linear polarization can still be obtained by alternately deploying left-handed and right-handed elliptically polarized patches. For validation of the proposed design, an array is fabricated with 16 elements on a substrate with 10 mil thickness and εr =2.2. The beamforming capability of the proposed array is also demonstrated. The experiment results agree well with the simulation and show that the antenna gain and the return loss bandwidth can be more than 21 dBi and 8%, respectively.

A design of 38 GHz planar phased patch array with sidelobe suppression for data-rate enhancement is proposed in the paper. The proposed array is formed of three 24-element subarrays of patches. Each patch has its own transmit/receive modules (TRM) consisting of a digitally controlled attenuator and phase shifter. In order to achieve high data-rate communications, the noise, especially due to the undesired signals received from the sidelobes, should be reduced with high sidelobe suppression of subarray. The sidelobe suppression of the proposed subarray is first improved to 17.92 dB with a diamond-shaped aperture and then better than 35 dB with a tapered radiation power distribution. The excellent sidelobe suppression of the antenna array is essential for the beam-division multiplexing applications when the signal sources are close to each other. The proposed design is validated experimentally, including the data-rate measurements showing that the 7 Gbps data transmission can be achieved with sufficient sidelobe suppression of the proposed design.