Related papers: Phased Array Feed Calibration, Beamforming and Ima…
Fourier ptychographic (FP) microscope is a coherent imaging method that can synthesize an image with a higher bandwidth using multiple low-bandwidth images captured at different spatial frequency regions. The method's demand for multiple…
We present the design, fabrication and measured performance of a hierarchical sinuous-antenna phased array coupled to transition-edge-sensor (TES) bolometers for measurements of the cosmic microwave background (CMB). To efficiently cover a…
In principle, diffractive optics, particularly Phase Fresnel Lenses (PFLs), offer the ability to construct large, diffraction-limited, and highly efficient X-ray/$\gamma$-ray telescopes, leading to dramatic improvement in angular resolution…
Context. Multi-element phased-array radio telescopes use digital beamforming to widen their field-of-view with numerous tied-array beams (TABs). These beams share bandpass variations and radio frequency interference (RFI). Yet, most pulsar…
FAST, the largest single-dish radio telescope in the world, has a 500-meter diameter main reflector and a 300-meter diameter illumination area. It has a shape variable main reflector, which changes the shape of the illuminated area in the…
Significant radar range degradation can be incurred due to variations in antenna impedance from changing array scan angle. Element-wise reconfigurable impedance tuners can be used to optimally match the power amplifier device; however, the…
The BICEP/Keck series of experiments target the Cosmic Microwave Background at degree-scale resolution from the South Pole. Over the next few years, the "Stage-3" BICEP Array (BA) telescope will improve the program's frequency coverage and…
Communication systems at millimeter-wave (mmW) and sub-terahertz frequencies are of increasing interest for future high-data rate networks. One critical challenge faced by phased array systems at these high frequencies is the efficiency of…
We present a multi-pass amplifier which passively compensates for distortions of the spherical phase front occurring in the active medium. The design is based on the Fourier transform propagation which makes the output beam parameters…
Millimeter wave is a promising technology for the next generation of wireless systems. As it is well-known for its high path loss, the systems working in this spectrum tend to exploit the shorter wavelength to equip the transceivers with a…
Microwave phased array antennas (PAAs) are very attractive to defense applications and high-speed wireless communications for their abilities of fast beam scanning and complex beam pattern control. However, traditional PAAs based on phase…
In this work, a planar phased array antenna was engineered with ultra-wideband (UWB) performance that covers portions of the L-, S-, and C-bands. The unit cell design contains a driven layer that is directly connected to a single coaxial…
Connected radio interferometers are sometimes used in the tied-array mode: signals from antenna elements are coherently added and the sum signal applied to a VLBI backend or pulsar processing machine. Usually there is no computer-controlled…
Interferometry with phased-array feeds (PAFs) presents new calibration challenges in comparison with single-pixel feeds. In particular, temporal instability of the compound beam patterns due to element gain drifts (EGDs) can produce…
Flat-top beam designs are essential for uniform power distribution over a wide angular sector for applications such as 5G/6G networks, beaconing, satellite communications, radar systems, etc. Low sidelobe levels with steep transitions allow…
Radio interferometers consisting of identical antennas arranged on a regular lattice permit fast Fourier transform beamforming, which reduces the correlation cost from $\mathcal{O}(n^2)$ in the number of antennas to $\mathcal{O}(n\log n)$.…
Integrated photonic active beamforming can significantly reduce the size and cost of coherent imagers for LiDAR and medical imaging applications. In current architectures, the complexity of photonic and electronic circuitry linearly…
A novel scalable pixel-based reconfigurable beamforming network (PRBFN) that can be used to form a Fluid Antenna System (FAS), referred to as a PRBFN-FAS, is introduced. The concept of FAS has emerged as an attractive new technology for use…
This paper describes the design of a 5.5:1 bandwidth feed antenna and reflector system, intended for use in hydrogen intensity mapping experiments. The system is optimized to reduce systematic effects that can arise in these experiments…
Infrared avalanche photodiode arrays represent a panacea for many branches of astronomy by enabling extremely low-noise, high-speed and even photon-counting measurements at near-infrared wavelengths. We recently demonstrated the use of an…