We present a resonant leaky-wave lens antenna, fed by a circular waveguide with annular corrugations in the ground plane. The proposed leaky-wave feed reduces the impact of the spurious TM0 leaky-wave mode in all planes over a wide bandwidth while reducing assembly complexity compared to previous methods. The proposed leaky-wave antenna has an aperture efficiency above 80%, a return loss below -15 dB, and a cross-polarization level below -20 dB over a bandwidth from 110-220 GHz (2:1). We have fabricated and measured a WR-5 band (140-220 GHz) antenna prototype with a lens diameter of 3 cm that achieves excellent agreement between measurement and simulation in terms of return loss, directivity, and gain.

A dual-polarized 4 x 4 scanning phased array antenna with leaky-wave enhanced lenses operating at 28 GHz is presented. Such an antenna can be used for point-to-point fifth-generation (5G) communications that require high gain, wide bandwidth (BW), and limited steering ranges. The proposed array has a periodicity of two wavelengths, and the resulting grating lobes are suppressed by directive and steerable array element patterns. To achieve a low-cost and low-profile solution, the leaky-wave antenna feeds are designed in printed circuit board and the lenses are made of plastic. The lenses are optimized in the near-field region of the feeds, with the goal of maximizing the array element aperture efficiency. The array performance obtained from the proposed approach is validated by full-wave simulations, showing a 27.5 dBi broadside gain at 28 GHz and a steering capability up to ±20° with 2 dB of scan loss. An antenna prototype was fabricated and measured. Measurement results are in excellent agreement with full-wave simulations. The prototype antenna, at broadside, achieves a 20% relative BW and a gain of 26.2 dBi.

In this article, we propose a hybrid electromechanical scanning lens antenna array architecture suitable for the steering of highly directive beams at submillimeter wavelengths with field-of-views (FoV) of ±25°. The concept relies on combining electronic phase shifting of a sparse array with a mechanical translation of a lens array. The use of a sparse-phased array significantly simplifies the RF front-end (number of active components, routing, thermal problems), while the translation of a lens array steers the element patterns to angles off-broadside, reducing the impact of grating lobes over a wide FoV. The mechanical translation required for the lens array is also significantly reduced compared to a single large lens, leading to faster and low-power mechanical implementation. In order to achieve wide bandwidth and large steering angles, a novel leaky wave lens feed concept is also implemented. A 550-GHz prototype was fabricated and measured demonstrating the scanning capabilities of the embedded element pattern and the radiation performance of the leaky wave fed antenna.

Ultra-wideband, three-dimensional (3D) imaging spectrometry in the millimeter–submillimeter (mm–submm) band is an essential tool for uncovering the dust-enshrouded portion of the cosmic history of star formation and galaxy evolution^1–3. However, it is challenging to scale up conventional coherent heterodyne receivers⁴ or free-space diffraction techniques⁵ to sufficient bandwidths (≥1 octave) and numbers of spatial pixels^2,3 (>10²). Here, we present the design and astronomical spectra of an intrinsically scalable, integrated superconducting spectrometer⁶, which covers 332–377 GHz with a spectral resolution of F/ΔF ~ 380. It combines the multiplexing advantage of microwave kinetic inductance detectors (MKIDs)⁷ with planar superconducting filters for dispersing the signal in a single, small superconducting integrated circuit. We demonstrate the two key applications for an instrument of this type: as an efficient redshift machine and as a fast multi-line spectral mapper of extended areas. The line detection sensitivity is in excellent agreement with the instrument design and laboratory performance, reaching the atmospheric foreground photon noise limit on-sky. The design can be scaled to bandwidths in excess of an octave, spectral resolution up to a few thousand and frequencies up to ~1.1 THz. The miniature chip footprint of a few cm² allows for compact multi-pixel spectral imagers, which would enable spectroscopic direct imaging and large-volume spectroscopic surveys that are several orders of magnitude faster than what is currently possible^1–3.

Terahertz spectrometers with a wide instantaneous frequency coverage for passive remote sensing are enormously attractive for many terahertz applications, such as astronomy, atmospheric science, and security. Here we demonstrate a wide-band terahertz spectrometer based on a single superconducting chip. The chip consists of an antenna coupled to a transmission line filterbank, with a microwave kinetic inductance detector behind each filter. Using frequency division multiplexing, all detectors are read-out simultaneously, creating a wide-band spectrometer with an instantaneous bandwidth of 45 GHz centered around 350 GHz. The spectrometer has a spectral resolution of F/ΔF =380 and reaches photon-noise limited sensitivity. We discuss the chip design and fabrication, as well as the system integration and testing. We confirm full system operation by the detection of an emission line spectrum of methanol gas. The proposed concept allows for spectroscopic radiation detection over large bandwidths and resolutions up to F/ΔF ∼ 1000, all using a chip area of a few cm². This will allow the construction of medium resolution imaging spectrometers with unprecedented speed and sensitivity.

In this contribution, we propose a hybrid electromechanical scanning antenna array architecture suitable for highly directive phased arrays at submillimeter wavelengths with field-of-views (FoV) of+/-30 degrees. The concept relies on combining electrical phase shifting of a sparse array with a mechanical translation of an array of lenses. The use of a sparse phased array significantly simplifies the RF front-end, while the translation of a lens array steers the element patterns to angles off-broadside, reducing the impact of grating lobes over a wide FoV. The mechanical movement of the lens array can be done using a low-weight, low-power piezo-actuator. In order to achieve wide bandwidth and steering angles, a novel leaky wave feed concept is also introduced. A 540 GHz prototype is currently under fabrication.

In this contribution, we propose an antenna for a dual-band focal plane array (FPA) heterodyne receiver at 210-240 GHz and 500-580 GHz to perform cometary observations. The proposed antenna is composed of a fused silica lens fed by a leaky wave waveguide feed. The dual-band leaky wave feed is based on a single-layer Frequency Selective Surface (FSS) with a transformer layer which allows to have a quasi-optical system that achieves a footprint of the field of view with overlapped beams and equal beamwidths for both frequency bands. A single pixel antenna prototype is currently being developed.

This papers discusses an effective framework for determining the number and direction of all possible grating lobes in the case of three-dimensional (3D) array antennas. Illustrating examples support the introduced theoretical concepts. The analysis highlights some intrinsic benefits of using 3D architectures, when compared with planar arrays. It also presents incentives for including the discussion of this class of conceptually relevant systems in (under)graduate curricula.

The (computational) complexity involved by beamforming in moving constellations of (nano) satellites is investigated by means of illustrative numerical experiments. While the number of radiators in such three-dimensional (3D) array antennas is not large, evaluating their radiation patterns entails challenging computational intricacies in view of the satellites being in motion and each satellite performing general 3D rotations. As a result, the relevant array radiation patterns become time-dependent, the elementary radiation patterns being themselves time-dependent. The discussed experiments will illustrate the time evolution of the radiation pattern for given individual satellite orbits and rotation laws. At the same time, they will provide a basis for estimating the computational complexity involved by predicting the complete beamforming in future space-bound remote sensing missions using constellations of (nano) satellites.