Frequency selective transmission scheme for EBG horn antennas

In this work a new integrated scheme of frequency selective transmission based on electromagnetic band gap (EBG) technology is presented. In the proposed configuration the radiofrequency signal is received by an EBG horn antenna and then filtered by an EBG cavity via the resonant coupling between two closed EBG waveguides and an EBG hollow defect (waveguide-to-cavity-to-waveguide coupling). The paper presents the designs of novel EBG horn antennas with competitive characteristics and demonstrates the concept of using different types of hollow EBG defects, such as point defects, void-like defects and tapers, for creating compact, efficient and integrated devices for submillimetre wavelenghts.4 page(s

Dispersion Properties of an Elliptical Patch with Cross-Shaped Aperture for Synchronized Propagation of Transverse Magnetic and Electric Surface Waves

This paper presents a novel pixel geometry for the implementation of metasurfaces requiring synchronized phase propagation of transverse magnetic (TM) and transverse electric (TE) modes. The pixel is composed by an elliptical metallic patch with an asymmetric cross-shaped aperture in the center, printed on a grounded slab. A practical implementation of a metasurface was carried out employing such a pixel geometry. Simulation results show similar frequency dispersion properties for both modes within the working frequency band, in agreement with the theoretical basis

A Millimeter-Wave 4th-Harmonic Schottky Diode Mixer with Integrated Local Oscillator

In this paper the design and experimental validation of a fourth-harmonic mixer based on Schottky diodes working around 300 GHz is presented. The main novelty of this work consists in the integration of an MMIC-based local oscillator, working around 75 GHz, and a mixer in the same metallic block housing. A prototype has been characterized using the Y-Factor method and yields a best measured conversion loss and an equivalent noise temperature of 14 dB and 9600 K, respectively. This performance is comparable to the state-of-the-art for this type of mixer

All-dielectric EBG horn antennas for submillimeter wavelength range

The paper is devoted to EBG horn antennas. This novel type of all-dielectric horn antennas is based on complex hollow defects in woodpile structures and can be used for creating compact arrays and provide a promising solution for submillimeter and terahertz devices. A novel concept of feeding EBG horn antennas via evanescent fields existing in periodic structures is presented. The principle of creating all-dielectric pyramidal horn antennas based on woodpile structure with hollow defects is proposed. Different horn antennas based on woodpile structures and characterized by large operating bandwidths and high levels of directivity and efficiency were designed, fabricated and measured.4 page(s

A Simplified Design Inline Microstrip-to-Waveguide Transition

A simplified design of an inline transition between microstrip and rectangular waveguide is presented in this paper. The transition makes use of a dielectric filled rectangular waveguide (DFRW) as an intermediate step, which simplifies manufacturing and allows for an analytical design. The behavior of the transition has been experimentally validated in the W-band by means of a back-to-back configuration. Good performance has been achieved: a return loss greaterthan 10 dB and mean insertion loss lower than 1 dB

Design of 300 GHz Combined Doubler/Subharmonic Mixer Based on Schottky Diodes with Integrated MMIC Based Local Oscillator

In this paper the design and experimental characterization of a combined doubler-subharmonic mixer based on Schottky diodes which uses a 75 GHz MMIC based local oscillator is presented. This solution integrates in the same substrate the doubler and the mixer, which share the same metallic packaging with the local oscillator. The prototype has been fabricated and measured. For characterization, the Y-Factor technique has been used and the prototype yields a best conversion loss and equivalent noise temperature of 11 dB and 1976 K, respectively, at 305 GHz. This performance is close to the state of the art, and shows the potential of this approach, which allows a significant reduction in terms of size and volume

Evanescently fed electromagnetic band-gap horn antennas and arrays

The design of a horn antenna based on electromagnetic band-gap structures (EBGs) and fed by evanescent fields in the containing periodic structure is presented. Such all-dielectric antennas can form compact arrays and provide a promising solution for millimeter, submillimeter, and terahertz (THz) devices. An evanescently fed EBG horn antenna design based on a woodpile structure and operating at frequencies around 110 GHz is presented, together with experimental and simulation results for an analogous scaled-up prototype antenna operating in the Ku-band. It exhibits a 9% bandwidth and an average level of maximum gain approximately equal to 14.6 dBi.10 page(s