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ABSTRACT: RF MEMS switches have improved electromagnetic properties compared to solid-state switches. Therefore, these devices are a promising alternative. Various designs have been studied, which show lower insertion loss in closed state (0.25 dB at 35 GHz), high isolation in open state (>14 dB at 30 GHz) and allow high power handling (>2.5 W at 5 GHz). Reliability and life-time are critical parameters of these new structures and little data are available today. This authors report on reliability and power handling investigations of the recently developed toggle switch, an ohmic contact switch. More than 2.4×10<sup>5</sup> switch cycles were successfully performed, the measured switch time was 12 μs and the release time was 25 μs. Contact resistances in the range of 5-16 ohm were measured and a temperature dependency of the pull-in voltage of -0.3 V/deg was observed.
IEE Proceedings - Microwaves Antennas and Propagation 11/2005; · 0.49 Impact Factor
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Microwave Conference, 2004. 34th European; 11/2004
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ABSTRACT: In the heterogeneous world of communication and radar systems, a steadily increasing number of technical approaches for different applications are observed. A new application on the horizon is the transmission of very high data rate streams (> 500 Mb/s) during a short time interval between moving clients. Such applications may be applicable to future intelligent traffic control systems based on R.D. Kuhne (2002) and will require the support of different standards for communication and radio location services. The high data rates require high bandwidths, which become available at millimeter wave frequencies. From an engineering point of view, we may not be unsatisfied with a growing number of tasks, however, economic aspects are forcing us to search for unified solutions that do not require reengineering for every new or modified application. Therefore, the goal is to shift functionality from hardware to software. For example, channel selection and demodulation can be implemented as software codes and are no longer hardware realizations. These software-defined radios (SDRs), which compute classical receiver functions, can be reconfigurable. Therefore, the need for hardware solutions that can handle several standards and related software implementations arises. It is the purpose of this article to compare two very promising solutions (sampling and six-port) with respect to their suitability in the millimeter-wave range and to discuss some related research aspects.
IEEE Microwave Magazine 04/2004; · 2.11 Impact Factor
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ABSTRACT: A serial combination of two different RF MEMS switch types is presented. This combination of an ohmic contact switch (toggle switch) and a capacitive coupling switch yields extreme broadband operation and exhibits low insertion loss (<0.5 dB at 20 GHz) and high isolation (>50 dB from DC to 50 GHz).
Electronics Letters 02/2004; · 0.96 Impact Factor
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ABSTRACT: A scaled, smaller version of the recently published toggle switch, an extremely broad band and highly linear ohmic RF MEMS switch for a frequency range from DC to 50 GHz, is presented. The electromagnetic simulation, the fabrication process, and measured results of the small toggle switch are given. The switch in its smaller geometry inherits the outstanding RF performances which could even be extended with an insertion loss of 0.95 dB and an isolation of 16 dB up to 50 GHz. These measurement results are in good agreement with the simulation. Power measurements results are in good agreement with the simulation. Power measurements (2 W) in the frequency range from 8 to 18 GHz did not show a self actuation of the switch.
Microwave Conference, 2003. 33rd European; 11/2003
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ABSTRACT: A software configurable receiver front-end based on six-port technology for a frequency range from 2 GHz to 20 GHz is presented. Its discriminator circuit is composed of coaxially connected and commercially available passive elements. Simulation and measurement results of quadrature phase shift keying (QPSK) demodulation tests at carrier frequencies between 2 GHz and 20 GHz are shown. Without the use of hardware filters and amplifiers data rates up to 1 Mbit/s can be demonstrated. The achieved low bit error rate (BER) proves the capability of this new concept for high bit rate wireless data links. For demodulation, a new packet based real-time calibration method was applied. Due to its inherent broad band properties, the proposed front-end is especially qualified for the realization of multi-standard, reconfigurable receiver platforms. An introduction to emerging six-port application is given. The functional principle of six-port receiver including the theoretical background is explained. Simulation and measurement results are discussed and possible improvements are pointed out.
Microwave Conference, 2003. 33rd European; 11/2003
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ABSTRACT: Limitations of existing receivers are the reason for the search for flexible receiver architectures. It is clear that the world of wireless communication systems and radar sensors will be heterogeneous in the future. Therefore, it arises the need for hardware solutions, which can handle several standards and related software implementations. Sampling architectures which sample the RF signal close to the antenna can provide a very flexible approach. Using a bandpass limited subsampling approach it is possible to investigate the basic feasibility of a ∞φ modulator approach at a carrier frequency of 24 GHz. The alternative six-port concept relies on an increased number of scalar measurements of the received signal and is basically suited for broadband applications. The signal is fed into power dividers, super-posed with a reference signal and the amplitude is measured at a minimum of 3 ports. Flexible signal generation will gain importance if different communication standards have to be supported. With direct digital synthesizers frequencies up to 2 GHz may now be reached.
Radio and Wireless Conference, 2003. RAWCON '03. Proceedings; 09/2003
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ABSTRACT: A single-pole-double-throw (SPDT) switch based on the toggle switch, a new type of radio frequency (RF) microelectromechanical (MEMS) switch structure for low voltage actuation, high broadband application and enhanced power capability, is presented. Electromagnetic simulation results are discussed and the fabrication process and measurement results are given. The SPDT switch exhibits low insertion loss (<0.5 dB at 20 GHz) and high isolation (>28 dB at 30 GHz).
Electronics Letters 05/2003; · 0.96 Impact Factor
