The safe operating area (SOA) of InGaP/GaAs heterojunction bipolar transistors has been studied using two-dimensional Technology Computer-Aided Design (TCAD) tool. Comprehensive physical models, including hydrodynamic transport-based impact ionization and self-heating models were implemented. The simulations for two DC modes (constant I and V modes) captured all the SOA features observed in measur

An accurate characterization of microwave materials is essential for reliable high-frequency circuit design. This paper presents a measurement setup, which enables a quick and accurate determination of the relative permittivity of dielectric bulk materials up to 110 GHz. A ring-resonator is manufactured on a well-characterized substrate, serving as reference resonator. The material under test (MUT

The front-end circuitry of transceiver modules is slowly being updated from GaAs-based monolithic microwave integrated circuits (MMICs) to Gallium-Nitride (GaN). Especially GaN power amplifiers and T/R switches, but also low-noise amplifiers (LNAs), offer significant performance improvement over GaAs components. Therefore it is interesting to also explore the possible advantages of a GaN mixer to

A 240-GHz monostatic circular polarized SiGe frequency-modulated continuous wave radar system based on a transceiver chip with a single on-chip antenna is presented. The radar transceiver front-end is implemented in a low-cost 0.13 µm SiGe HBT technology version with cut-off frequencies f/f of 300/450 GHz. The transmit block comprises a wideband ×16 frequency multiplier chain, a three-stage PA, wh

In this work, a voltage tunable interdigital capacitor loaded with liquid crystal (LC) is investigated and its application for a composite right/left-handed leaky-wave antenna (LWA) is demonstrated. The tuning capability of the varactor is confirmed by simulation and measurement. A material tunability of 25% of the used LC yields a measured varactor tunability of 9%. Based on this, a tunable LWA w

In the following, a continuous wave radar system based on the Six-port principle will be shown for measurement tasks at enclosed systems needing micrometer accuracy as well as high update rates like tank level monitoring or hydraulic cylinder piston control. To exceed the ambiguity limit of such an interferometric system, a dual tone approach is used. The system will be presented with measurement

A compact and broadband TE-TE-mode converter, suitable for various industrial applications like bypass level measurements, is presented in this contribution. Based on stepped waveguide technique, the main advantages of the recommended converter design and the specific field distribution of the TE-mode are discussed in detail. The converter is presented exemplary for a frequency range from 23 to 28

A new technique to realize quasi-elliptic bandpass filters with extreme close-in rejection is presented in this paper. The basic idea consists of embedding non-resonating mode waveguide cavities within the structure of an evanescent-mode filter. Such a combination of cavities and resonators allows the generation of very close transmission zeros while realizing at the same time relatively wide pass

In this paper, the design and test of a single-chip RF pulse-width modulator and driver (PWMD) aimed at exciting a high-power class-E GaN high-power stage at 435 MHz is described. For the required buffer size, avoiding potential ringing of the pulses within the buffer structure presents a major challenge in the design process. Therefore, a smaller test chip capable of driving capacitive loads of u

In this paper, we present several dielectric waveguide (DWG setups that enable the transition between radar front ends and antennas in challenging, industrial environments. Apart from good propagation behavior, DWG provide a nearly dispersion free transmission over large distances. Furthermore, they can be used as an electrical insulator in places with critical creep distances, in high temperature