This paper presents an optimization method for pattern synthesis of distorted phased array antenna with unsteady surface deformation considering the dynamic range ratio (DRR). In the synthesis approach, different array deformations under unsteady mechanical loads are considered, and the distorted distribution of array elements is calculated after solving the mechanical deformation model. Then, optimize the excitation coefficients of each array element including amplitude and phase with DRR control so as to recover a high-quality pattern from a deteriorated pattern caused by the unsteady deformations. The optimization objective is to minimize the peak sidelobe level, which is synthesized by using a gradient-based algorithm. The optimized excitations can be used as the initial excitation, and the corresponding phase excitations can be derived according to the different deformations.

Due to the advent of high-throughput communication satellites in a geostationary orbit, the development of multiple beam phased array antenna (MBPAA) technology has become a necessity. This paper presents the design and implementation of the constituent unit of a beamforming network (BFN), which feeds an MBPAA with interleaved sub-arrays. The proposed BFN generates multiple orthogonal sub-beams with a very tiny angular distance between adjacent sub-beams in a limited field of view. The BFN consists of sub-array beamforming networks (SABFNs) with unequal number of beam ports and antenna ports, which can feed both the arrays lateral elements and the interleaved core sub-arrays for pattern shaping and side-lobe level reduction. A microwave circuit for this SABFN has been designed and fabricated in C-band. The microstrip lines have been printed on the two sides of a suspended substrate. This technique leads to size reduction of the circuit by twice a value compared to a conventional microstrip circuit. Measurements have been compared to simulations, and good conformity has been observed. The insertion loss in the path of beam ports to the antenna ports is 3.5 dB for a relative bandwidth of 10%.

Achieving robust and fast two-dimensional adaptive beamforming of phased array antennas is a challenging problem due to its high-computational complexity. To address this problem, a deep-learning-based beamforming method is presented in this paper. In particular, the optimum weight vector is computed by modeling the problem as a convolutional neural network (CNN), which is trained with I/O pairs obtained from the optimum Wiener solution. In order to exhibit the robustness of the new technique, it is applied on an 8 × 8 phased array antenna and compared with a shallow (non-deep) neural network namely, radial basis function neural network. The results reveal that the CNN leads to nearly optimal Wiener weights even in the presence of array imperfections.

Sub-beam concept is very useful for size reduction of multiple beam phased array antenna (PAA) systems that are applied for high-throughput communication satellites. In this paper, the synthesis procedure for a PAA with multiple sub-beams in two dimensions of the coverage domain is proposed and analyzed. In the design procedure, the interleaved sub-arraying technique has been applied to eliminate the grating lobes. The extremely short angular distance between adjacent sub-beams is challenging. An innovative beam forming network is proposed, which can generate multiple orthogonal sub-beams while keeping the required angular distance between sub-beams. To demonstrate the effectiveness of the design technique, an example considering the requirements derived from conceptual design of a high-throughput communication payload is presented. The array is optimized using the genetic algorithm while taking into account the technical requirements of the antenna. The gain patterns exhibit a 0.4° angular distance between adjacent sub-beams. In addition, the number of sub-arrays and element spacing guarantee the orthogonality of the sub-beams. The calculated carrier to interference ratio in the synthesized array shows that it has acceptable values in each spot. The aperture size reduction in the synthesized array compared to a conventional multiple beam array is more than 36.7%.

The paper describes the design and development of a low profile wide scanned conformal active 1 × 32 phased array antenna for Ku-band SATCOM applications. The realized antenna is diagonally polarized and covers full transmit frequency band (i.e. 13.75–14.5 GHz) of Ku band SATCOM. All the developed sub-systems of the antenna, i.e. conformal radiating array, conformal transmit module, manifold network, and beam steering unit are described. The VSWR of the antenna is better than 1.65 over the complete transmit frequency band. The antenna has the beam steering capability of ±60° in the array plane. Designed antenna is best suited for airborne applications, where antenna profile contributes considerable aero drag and RCS to the host platform.

We proposed and examined a microwave power transfer system for electric vehicles (EVs). In this system, electricity is transmitted from a transmitting antenna over an EV to a receiving antenna on the roof of the EV. We used a rectenna to convert the received microwave power to direct current power. The conversion efficiency of a rectenna array is affected by the input power level distribution, and we have to form a flat-topped beam pattern to increase the conversion efficiency. We conducted an experiment to form a flat-topped beam pattern by using a phased array antenna. In this experiment, the output power of each antenna element is uniform and cannot be controlled independently. Hence, we controlled only the output phases of each antenna element and formed a flat-topped beam pattern. The distance between the transmitting antenna and the receiving area is 6.45 m, and the receiving area corresponds to a space in which the azimuth and elevation are in the range of −5°–5°.

Detailed analysis of the polarization tracking modules for Ku band active phased array antennas is presented. The proposed transmitter (14.0–14.5 GHz) and receiver (12.25–12.75 GHz) modules are based on the low temperature co-fired ceramic (LTCC) technique, containing orthogonal dual channels with different phases controlled by phase shifters. The effect of amplitude and phase inconsistency between two channels on polarization tracking performance is analyzed. The validity of the analysis is verified by the measurements of the manufactured prototypes. The measured patterns of the active phased array antenna are given to illustrate the effects of the modules on polarization agility, which may be used for Ku band satellite antennas on mobile terminals.