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The synthesis of the sub-array phases for multi-beams scanning applications is here addressed. A hybrid analog/digital architecture is considered in which analog element excitations are used to generate a reference beam, while a digital sub-arrayed beam-forming network (BFN) is used for steering a secondary beam within a limited scan cone. The digital phases are obtained through an innovative analytic...
A low cost phased array operating from 8 to 12 GHz is demonstrated. The designed phased array consists of a stripline fed 1×4 H-plane Vivaldi antenna array, monolithic microwave integrated circuit (MMIC) switched-line phase shifters, and a broadband power divider. The 1×4 H-plane Vivaldi antenna array provides a directivity of 8 dBi. For the best beam steering performance, calibrated phases in anechoic...
The optimization and design process for an isoflux phased array for Cubesats in low earth orbit (LEO) is presented. A genetic algorithm is used to create a multi-ring concentric circular phased array that creates a near-isoflux power pattern on the earth surface. At high operating frequencies, the array is small enough to fit on the 1U face of a Cubesat. Simple microstrip patch antennas are used for...
This paper presents a new class of electromagnetic bandgap material, which is mode-free along the all lateral directions while radiating as an antenna element towards the broadside direction at the bandgap frequency region. It is an ideal antenna element to eliminate substrate wave effects, i.e. mutual coupling and scan blindness, from microstrip phased arrays.
An ultra-wideband low-phase noise local oscillator (LO) for the phased array antenna system operating from 11 GHz to 19 GHz is proposed. A phase-locked loop (PLL) frequency synthesizer is adopted in the design where a 100 MHz crystal oscillator is used as a reference frequency. Experiment results show that the output of the ultra-wideband LO agrees well to the predicted results with high stability...
A dual circularly polarized wideband array working over a 2:1 bandwidth was previously developed. This array had the following requirements: 2:1 bandwidth, capable of steering up to 30° in theta, dual circular polarization, Relative Sidelobe Level (RSLL) < −10dB, Axial Ratio (AR) < 3dB and reflection coefficient (S11) < −10dB. In this paper, we extend the array bandwidth to 15:1 through adding...
Design considerations on a wide-scanning array antenna for on-craft satellite communications are presented in this paper. For this type of application, a scanning coverage of 80° over a 15% fractional bandwidth in Ka-band is required. A solution based on a passive superstrate illuminated by a phased array is recognized as the most encouraging. Two kinds of structures are investigated: a flat solution...
A new type and multifunctional electromagnetic bandgap material, i.e. bandgap-antenna structure, is used as an antenna element in a planar phased array configuration. The structure provides mode-free bandgap, antenna, and phased array element characteristics simultaneously. A stripline impedance matching network is used to match bandgap-antenna element's input impedance. The phased array eliminates...
A family of uniformly distributed antenna arrays is analyzed probabilistically. This yields a novel method for characterizing mean-valued performance, including ensemble average progressions for the sophisticated array factors of range Doppler routines, radar cross sections, and quadratic phase variations providing hyperfocal range characteristics. Array factors and hyperfocal distances rH are derived...
In this paper, we discuss the limitations of phased arrays for 5G massive MIMO systems. The multibeam radiation patterns produced by a full phased array, a phased array with fixed sub-arrays, and a phased array with segmented phased sub-arrays are compared via illustrative examples. In fact, conventional phased array can only improve the link gain or the coverage, but couldn't enhance the capacity...
A 1×4 phased array antenna in package is presented at 60 GHz frequency band. End-fire elements are double side dipoles which provide a near omni-directional beam in H-plane. In E-plane, the phased array facilitates ±45° beam steering which improves the spatial coverage. The achieved end-fire gain is 9.1 dBi and both impedance and gain bandwidths cover all WiGig channels. The wide bandwidth, high coverage,...
A novel decoupling method for a quasi-Yagi antenna array using partial reflection metal strips is proposed. These reflection metal strips, a kind of Array-antenna Decoupling Surface (ADS), can be designed to cancel the unwanted coupled waves among adjacent antenna elements. A prototype of a four elements quasi-Yagi antenna array with about λ/2 spacing and a decoupling surface is prototyped on an FR4...
We present a low profile (λLOW/8) wideband slot spiral antenna array with high transmit/receive (Tx/Rx) isolation and scanning capability for STAR systems. To our knowledge, this is the first wideband STAR array with circular polarization and scanning capability. By suppressing Tx/Rx coupling, this array provides true full-duplex radios with a wideband beam steering antenna. Each array spiral consists...
A high level design of a smart wireless energy harvesting system is presented. The energy harvesting system is designed to be adaptive to varying loads and input powers. The system also utilizes a phased array antenna to adaptively scan the beam for maximum power tracking. Simulated and experimental results for the major subsystems of the harvester are presented.
A wideband dual-polarized Vivaldi antenna with 60 degree scan capability is presented with full wave analysis results. Several mechanical criteria are satisfied in order to make the antenna fabrication very easy and affordable using EDM technique in 3 axes. The antenna active input impedance and active polarization isolation are also optimized to prevent losses due to polarization to polarization...
A novel method, which is based on two port transmission along a semi-infinite array of antenna elements, is presented here to analyze substrate waves, i.e. leaky or surface wave modes, in the microstrip phased arrays. The method takes all types of loadings, i.e. feeding or any other types of metallization, into account. The phased array elements can be excited, and the effect of the excitation phases...
A novel, travelling-wave, waveguide antenna structure with monopulse capability in the two principal planes is proposed with increased frequency bandwidth. The array consists of two interleaved waveguide arrays which provide appropriate excitations to the antenna elements above the waveguide to generate proper sum and difference patterns. With the use of printed antennas and the elimination of the...
Electromagnetic ultrasonic transducers (EMATs) phased arrays technology is helpful to improve the sensitivity and efficiency of defect detection, and the performance can be evaluated by the directivity of steering beam. The directivity is affected by transducer parameters such as number of elements, element width, and inter-element spacing. Therefore, the effects of element parameters on the directivity...
In this paper, a L-band phased array radiometer for sea surface salinity is developed. To reduce the mass and volume of real-aperture microwave radiometers, the radiometer employs a phased array and a receiver channel, which can observe target scenes with electric scanning. The L-band phased radiometer is analyzed using noise waves. The calibration method of the radiometer is introduced. A Radio Frequency...
In this paper, a beamforming system for LTE- Advanced based on Array sampling technology is proposed. Antenna Array that has been designed covers LTE mid and high bands. RF multiplexer 8x1 switch has been designed and simulated. The system is composed of agile RF frontend and FPGA digital signal processing unit.
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