Patrick Schuh

Robust X-band low noise limiting amplifiers

GaN technology is today well established for power amplifiers but also for robust receiver components. In this paper we present the design and measurement results of two different robust LNAs with different limiter functionalities included. One version with 1.6 dB noise figure which survives 4W input power and with the included current limiter the maximum output power is only 17dBm. The other version with input limiter survives more than 10W input power with a noise figure of 2 dB.

An approach to accurate measurements of the electrical characteristics of SAW RF filters using neutral test environments

The paper discusses and classifies typical measurement setups used for the precise electrical characterization of surface acoustic wave (SAW) radio frequency (RF) components, such as, e.g., SAW filters and duplexers, in the context of nowadays demand for increased accuracy of measured filter data. The measurement setups are divided into test environments and application environments. By means of a couple of case studies the paper exemplifies the impact of printed circuit boards (PCBs) on the measured electrical filter characteristics. The effects observed are investigated by measurements and simulation. Simulation models established and analyzed take both relevant electromagnetic and acoustic effects into account. Comparisons of measurements and simulations indicate excellent agreement. The paper points out the necessity for measurement setups that provide a neutral environment to the filter. Here, the notion neutral environment implies minimal reflections, minimal feed-through or cross-talk, and minimal losses. It concludes with the proposal of a neutral environment, which has been successfully implemented in a couple of use cases. Performing the measurement using a neutral environment allows the determination of the filter characteristics without effects caused by the PCB, which is considered an essential prerequisite for an engineering approach to a modular design of a complex system, such as, e.g., the RF section of a mobile terminal.

Full-wave Characterisation of RF Ceramic Packages

The characterization of small complex ceramic packages with (monolithically) integrated microwave circuits is investigated using full-wave methods. In order to correctly design packaged radio frequency (RF) chips, the consideration of the package has become an indispendible part of the chip design process, as the electrical properties of the package have a great impact on the performance of the RF chips. For an effective simulation, a segmentation between the chip and its immediate environment, such as, the package, is investigated, and a suitable interface between chip and package is proposed to prove the validity of the interface, the simulation of the packaged RF device, which is pieced together from the full-wave simulation of the package and the simulation of the RF chip, is compared to the corresponding measurement. Simulation and measurement of the packaged RF device agree very well.

Some Investigations of a Novel Type of mm-Wave Frequency Divider

A new concept for mm-wave frequency dividers with higher division ratio based on a harmonic mixer and a PLL circuit is demonstrated. Its function and perfonnance was tested in Ka-Band, but it principally can be extended to higher frequencies. At 30 GHz, a division ratio of 17 was realized over a bandwidth of 1.4 GHz at -14 dBm input power level.