In this paper, we present a quasi-optical power distribution architecture based on the use of an integrated lens antenna that generates a uniform aperture field distribution. By using such distribution in combination with an integrated lens array, an efficient and scalable quasi-optical power distribution can be achieved at THz frequencies. The proposed architecture is based on a leaky-wave waveguide feed that illuminates an elliptical lens with a top-hat distribution. This method can distribute the power from one antenna to a 7-pixel lens array in a hexagonal configuration with a power coupling efficiency of nearly 60%. This scheme could be potentially used for the local oscillator power distribution in heterodyne THz arrays. A prototype at 450-615GHz has been developed and characterized, achieving an aperture efficiency higher than 80%.

The development of a low focal number and low-mass lens antenna is presented that enables terahertz spectroscopy applications on ultracompact platforms. The antenna operates efficiently over a 20% fractional bandwidth, from 450 to 550 GHz, with a gain of 50 dBi at 500 GHz. The antenna consists of a hyperbolic silicon lens that is placed in a record low focal number configuration (f_#=0.27) with respect to an advanced waveguide feed. An incident field-matching analysis is applied to investigate the optimal feed radiation pattern that maximizes the lens aperture efficiency, which would result in a 20% increase in aperture efficiency (> 80%) with respect to a standard open-ended waveguide (< 60% aperture efficiency). A multilayer leaky-wave (LW) stratification is quasi-analytically optimized to approximate the optimal feeding pattern, resulting in a >70% lens aperture efficiency. An example LW stratification is synthesized using silicon micromachining technology and is fully characterized in combination with the dielectric lens.

This article presents a low-loss silicon microelectrical mechanical system (MEMS) phase shifter operating in the 500-600 GHz band. The phase shifter consists of a \text{30-}\mu \text{m} thick perforated silicon slab that is moved in and out of a waveguide in the E-plane with a large deflection MEMS actuator. By implementing different hexagonal patterns in the silicon slab, a stepped permittivity is created to impedance match, and thus, reduce return loss. When the silicon slab is inserted into the waveguide, the phase velocity of the incoming wave is decreased, thus resulting in different phase shifts depending on the position of the slab inside the waveguide. The MEMS phase shifter is fully actuated at around 50\,{\text{V}} and can move up to \pm 95\,\mu \text{m}, depending on the applied voltage. The insertion loss, when the maximum phase shift is achieved, is measured to be \text{1.8}\,\text{dB}, compared to a 1.6\text{-}\text{dB} insertion loss for a waveguide of equivalent length. The return loss is better than \text{18}\,\text{dB} for the desired band. The measured phase shift, with the slab fully inserted into the waveguide at \text{550}\,\text{GHz} was 145^\circ. The MEMS phase shifter enables a variety of applications including phased array antenna systems with scanning capability for mapping of planetary surfaces with an electronically steerable antenna.

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.

It is difficult to package and interconnect components and devices at millimeter-waves (mm-waves) due to excessive losses experiences at these frequencies using traditional techniques. The problem is multiplied manifold at terahertz (THz) frequencies. In this article, we review the current state of THz packaging and describe several novel techniques. As we will show, micromachined packaging is emerging as one of the best choices for developing advanced THz systems.

In this review paper we explore different antenna technologies at terahertz frequencies for space science and other applications. We show that the antenna technologies generally used at lower frequencies are difficult to implement at terahertz frequencies. Additionally, one has to take a few extra steps and special care for designing antennas for space-based applications. In this paper, we review different design and implementation options for millimeter-wave and terahertz antennas for space applications. We detail how antenna design has to be a part of the overall system design for the success of the instruments for space missions. We also look into low-mass and low-profile conformal antenna technologies that will have a profound impact on future space instruments at terahertz frequencies.

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 paper presents a lens antenna that scans the beam using an integrated piezomotor at submillimeter-wave frequencies. The lens antenna is based on the concept presented by Llombart et al. in 2011, a leaky-wave waveguide feed in order to achieve wide angle scanning and seamless integration with the receiver. The lens is translated from the origin of the waveguide producing the scanning of the beam over a 50° field of view (FoV) (or about 6.25 beamwidths) with a maximum scanning loss of 1 dB. The lens movement is achieved with a piezoelectric motor that is integrated within the antenna and receiver block. A prototype was built and measured at 550 GHz achieving scanning beam angles close to 20° with only 0.6 dB of loss. The scanning of the 50° FoV, which corresponds to a lens displacement of approximately 2 mm, takes about 0.9 s achieving a scanning rate of 0.75 Hz of the FoV. The accuracy in continuous mode of the piezoactuator has been measured to be less than 28 μ in the worse of cases for displacements of 2 mm, which corresponds to a beam steering of 0.76°, much smaller than the antenna half-power beamwidth of 8°.

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.

This paper describes the design and realization of a modulated metasurface (MTS) antenna at 300 GHz. To overcome the hurdles associated with the use of dielectric substrates in the sub-millimeter wave range, we propose an MTS structure which consists of an array of metalized cylinders placed on a ground plane. The metal cylinders are arranged in a square lattice with sub-wavelength unit cell size. This MTS topology has been successfully used to design a spiral MTS antenna. The resulting structure has been micromachined out of a silicon wafer by means of deep reactive ion etching (DRIE). The performance of the antenna has been verified by full-wave simulations, and measurements will be available at the time of the conference.

Using newly developed silicon micromachining technology that enables low-loss and highly integrated packaging solutions, we are developing vertically stacked transmitters and receivers at terahertz frequencies that can be used for communication and other terahertz systems. Although there are multiple ways to address the problem of interconnect and packaging solutions at these frequencies, such as system-on-package (SOP), multi-chip modules (MCM), substrate integrated waveguide (SIW), liquid crystal polymer (LCP) based multilayer technologies, and others, we show that deep reactive ion etching (DRIE) based silicon micromachining with vertical integration allows the most effective solutions at terahertz frequencies.

The development at 1.9 THz of a microlens antenna consisting of a leaky-wave waveguide feeding and a silicon microlens is presented in this paper. The antenna has excellent performances compared to horn antennas and can be fabricated entirely using silicon micromachining. Two antenna prototypes were developed: one with a 2.6-mm-diameter microlens and a directivity of 33.2 dB and the other with a 6.35-mm-diameter microlens and a directivity of 41.2 dB. Both prototypes were fabricated and measured, obtaining good agreements with simulations. The fabrication, assembly, and measurement process are explained and detailed in this paper.

Using newly developed silicon micromachining technology that enables low-mass and highly integrated receivers, we are developing state-of-the-art terahertz spectrometer instruments for space-based planetary and astrophysics orbiter missions. Our flexible receiver with integrated antenna architecture provides a powerful instrument capability in a light-weight, low-power consuming compact package which offer unprecedented sensitivity performance, spectral coverage, and scalability to meet the scientific requirements of multiple missions.

We explore the use of a class of metasurface (MTS), which consists of metalized cylinders arranged in a square lattice and placed on a ground plane, for the realization of antennas at terahertz (THz) frequencies. This MTS is particularly appropriate for being micromachined out of a silicon wafer by means of deep reactive ion etching (DRIE).