Christian Rave

A wideband radial substrate integrated power divider at K-band

A wideband 1:7 radial power divider for operation at K-band is proposed. The divider features a radial substrate integrated waveguide (SIW) cavity enclosed in a multilayer printed circuit board (PCB) as well as microstrip matching structures and feed-lines on the top and bottom layers. The divider is designed using standard high-frequency substrate. Including the outer vias, the divider cavity has a diameter of about 7 mm. Thus a compact design is achieved. Measurement and simulation results are presented. The measured -10 dB reflection bandwidth of the divider is 9 GHz or 45% with a center frequency of 20 GHz.

3D-printed low-cost, low-loss microwave components up to 40 GHz

This contribution investigates the manufacturability and the performance of waveguide components fabricated using a consumer-grade 3D printer. This low-cost process enables a fast fabrication of microwave circuits almost directly from a 3D simulation model to a ready-to-use component. Two different components, a simple waveguide and a more complex array with integrated power combiner, are manufactured and characterized to validate the approach.

Substrate-Integrated-Waveguide E-Plane 3-dB Power-Divider/Combiner Based on Resistive Layers

Several different microwave circuits, including beamforming networks and balanced amplifiers, make use of 3-dB power dividers and combiners. A well-known architecture able to work over large bandwidths, a critical request for many applications, is based on E-plane three-port waveguide structures, where a lossy element is added to overcome the inherently poor isolation given by lossless three-port junctions. While a standard implementation based on normal rectangular waveguides often results in large and heavy structures, an implementation based on substrate-integrated-waveguide (SIW) technology offers advantages in terms of compactness, weight reduction, cost minimization, and integration possibilities with active stages. This paper presents the design, fabrication, and characterization of two SIW E-plane 3-dB power divider/combiners where the lossy element is realized using a resistive layer. The prototypes cover the entire

A substrate integrated matched load with embedded resistive thick film

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Active multi-feed satcom systems with GaN SSPA at K-band

-band from 8 to 12 GHz, and the resistive layers are realized according to two different manufacturing techniques to investigate the potentials of both approaches. The optimization of the resistive layer geometry and resistivity, a critical aspect for low-profile SIW circuits, is discussed in detail. In particular, an analytical formula is derived, which allows to determine the optimum values for the resistive layers’ principal parameters, namely the length and resistivity, without the use of full-wave numerical solvers.

A Design Approach for Tapered Waveguide to Substrate-Integrated Waveguide Transitions

A matched load in substrate integrated waveguide (SIW) technology is presented at K-band. An embedded resistive thick film is used to absorb the input signal. The proposed structure is fully compatible with standard multilayer printed circuit board processes. The realized SIW termination exhibits a bandwidth of 2.75 GHz with a return loss of more than 20 dB around 18.4 GHz.

Architectures for efficient power sharing in active multiple-feed-per-beam satellite antennas

The ongoing developments of satellite antenna technology, mainly of multiple-feed-per-beam (MFB) concepts, combined with advanced compound semiconductor and packaging technologies that provide the building blocks for a new generation of K-band satellites, are reported. This paper proposes a next-generation MFB application scenario using the advantages of both new antenna and solid-state power amplifier concepts.

A Compact Bandpass Filter Integrated SPDT PIN Switch at X-Band

A design approach for substrate-integrated waveguide (SIW) to rectangular waveguide (RWG) transitions based on the synthesis of antipodal finline tapers is proposed. The taper is designed using a reflection-based impedance definition as no suitable model is available for antipodal finlines. The characteristics of the finline are determined from full-wave simulation. To demonstrate the proposed method, two SIW-to-RWG transitions are designed and characterized at the K-band. The measured back-to-back transitions exhibit a return loss above 15 dB and an insertion loss below 1 dB between 16.7 and 20.5 GHz and between 21.1 and more than 31 GHz, respectively. A good agreement between the synthesis model and full-wave simulation of the taper on one hand and between simulation and measurements of back-to-back transitions on the other hand is demonstrated.

A multilayer substrate integrated 3 dB power divider with embedded thick film resistor

Architectures for active multiple-feed-per-beam satellite antennas with power amplifiers shared between adjacent beams are presented. Different concepts for sharing solid state power amplifiers (SSPAs) to reduce required power margins for a K-band scenario are proposed and compared. In scenarios with data traffic and rain attenuation unequally distributed across the beams the overall efficiency can be increased.