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TNO has a long heritage in the research and development of radio frequency (RF) and microwave technology for phased array systems, ranging from high-level system design to hardware design, including integrated circuits and antennas. Customers include the Dutch ministries, the European Union (EU) and the European Space Agency (ESA). Innovative RF technology solutions are developed to tackle the key challenges posed by future space missions, particularly for Satellite Communication and Earth Observation. For this, TNO works in close co-operation with large space system integrators, and collaborates with other Dutch research institutes and industry. In this article a number of such developments, some performed for ESA, are presented, with recent project examples covering antenna design, Monolithic Microwave Integrated Circuit (MMIC) design and RF module design.

This paper presents the design and measurement results of a single-chip front-end monolithic microwave integrated circuit (MMIC), incorporating a high-power amplifier, transmit– receive switch, low-noise amplifier, and calibration coupler,realized in 0.25 μm AlGaN/GaN-on-SiC MMIC technology of UMS (GH25-10). The MMIC is operating in C-band (5.2–5.6 GHz) and is targeting the next generation spaceborne synthetic aperture radar. The use of GaN technology has resulted in a design that is robust against antenna load variation in transmit as well as against high received power levels, without the need for an additional limiter. By including a transmit–receive switch on the MMIC there is no need for an external circulator, resulting in a significant size and weight reduction of the transmit–receive module. The measured output power in transmit is higher than 40 W with 36% PAE. The receive gain is higher than 31 dB with better than 2.4 dB noise figure. To the best of the author’s knowledge this is the first time such performance has been demonstrated for a single-chip implementation of a C-band transmit–receive front-end.

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 enable a fully GaN-based front-end. In this paper, the design-experiment and measurement results of a double-balanced image-reject mixer MMIC in 0.25 mm AlGaN/GaN technology are presented. First an introduction is given on the selection and dimensioning of the mixer core, in relation to the linearity and conversion loss. At the intermediate frequency (IF)-side of the mixer, an active balun has been used to compensate partly for the loss of the mixer. An on-chip local-oscillator (LO) signal amplifier has been incorporated so that the mixer can function with 0 dBm LO input power. After the discussion of the circuit design the measurement results are presented. The performance of the mixer core and passive elements has been demonstrated by measurements on a test-structure. The mixer MMIC measured conversion loss is ,8 dB from 6 to 12 GHz, at 1 GHz IF and 0 dBm LO power. The measured image rejection is better than 30 dB.

Solid-state power amplifiers need protection at the output to handle high reflections due to mismatch. Normally this is implemented by using a ferrite-based isolator. These are however large and bulky components. This paper presents a Gallium-Nitride power amplifier module with automatic protection against large reflections based on fold-back protection, by sensing the reflected power. Measurements have been performed on a 100 W L-band power amplifier module at full reflection (short at the output) without damage to the amplifier. The reaction time of the protection mechanism is less than 0.5 μs.

In space applications, due to the large number of sources of interferences, RF receivers have to be as robust as possible to maintain good operation of the satellite. The system must maintain its performance under severe jamming conditions and the performance must not degrade when exposed to high input powers. To address the receivers’ robustness, LNAs and Mixers have been designed and fabricated in the frame of an European project. TNO and TAS-F have been in charge of the amplification and mixing parts respectively. Three frequency bands are targeted for these designs: C-, Ku- and Ka-band. Gallium Nitride [8] has the advantage of high power capabilities and low noise performance, which makes it an excellent candidate for robust satellite receivers. High survivability levels for LNAs by using GaN technology has already been proven by others [1]-[7]. Regarding mixers in GaN, only a few designs have been published [9]. For both MMICs, the AlGaN/GaN technology is used with gate length of 0.25 μm and 0.15 μm provided by Fraunhofer IAF. The measured performance for the LNAs is a noise figure of 1.2, 1.9 and 4dB for the C-, Ku- and Ka-band respectively, with a gain of 21, 19.8 and 18dB. For the Mixers, the conversion losses are 10, 9 and 12dB with a 12, 11 and 8dBm for the input 1dB compression point. This paper presents the design and measurement results of the C-, Ku-, Ka-band LNAs and Mixers.

This paper presents the initial results in a study aimed at exploring the use of GaN-devices in applications where they are at risk of being exposed to high output voltage-standing-wave-ratio (VSWR) conditions. A measurement method developed to identify the limits of such stress is described together with the first results from measurements of novel FBH GaN-HEMT technology. Furthermore a circuit design aimed at preventing excessive operation under high output VSWR conditions is presented. The first findings suggest that the investigated devices are very robust to VSWR stress and the suggested protection circuit with a power-down cycle in the 100 ns range is sufficient to ensure a long lifetime with little degradation of RF performance.

In this paper a novel low-cost SMD package for high-power MMICs is presented. Due to the special design this package has a very low thermal resistance and low parasitic ground inductance. 3D EM simulations of a packaged through-line correspond well with measurements. Measurement results of a 1 Watt 40 GHz HPA before and after packaging are presented. The gain reduction at 40 GHz caused by the package is only 1 dB. Experimental results are given for different package options: with or without compensation circuit on the package and with or without bondwire compensation on the MMIC.

This paper presents a novel approach to realize low-cost millimeter-wave modules using only SMD packaged MMICs integrated on a single organic substrate. This approach is demonstrated on a 38 GHz transceiver module for point-to-point LMDS communication systems. The required SMD package technology and demonstrator have been developed in the 5th framework European IST project "Surface Mount Assembly for Communication K-band Systems" (SMACKS). Two types of SMD packages have been developed based on LTCC technology for the low-power devices and an organic package for the high-power amplifier. The use of only packaged devices enables low-cost module manufacturing without the need for specialized equipment and without yield loss from handling bare die MMICs. The estimated cost reduction of such a module, with respect to a module using bare die components and mixed substrate technologies, is around 20%. A disadvantage of this approach is that the density of integration is low, since each active device is housed in its own package.

More and more system-on-chip designs require the integration of analog circuits on large digital chips and will therefore suffer from substrate noise coupling. To investigate the impact of substrate noise on analog circuits, information is needed about digital substrate noise generation. In this paper, a recently proposed simulation methodology to estimate the time-domain waveform of the substrate noise is applied to an 86-Kgate CMOS ASIC on a low-ohmic epi-type substrate. These simulation results have been compared with substrate noise measurements on this ASIC and the difference between the simulated and measured substrate noise rms voltage is less than 10%. The simulated time domain waveform and frequency spectrum of the substrate noise correspond well with the measurements, indicating the validity of this simulation methodology. Both measurements and simulations have been used to analyze the substrate noise generation in more detail. It has been found that direct noise coupling from the on-chip power supply to the substrate dominates the substrate noise generation and that more than 80% of the substrate noise is generated by simultaneous switching of the core cells. By varying the parameters of the simulation model, it has been concluded that a flip-chip packaging technique can reduce the substrate noise rms voltage by two orders of magnitude when compared to traditional wirebonding.