We demonstrated that 3D quasiperiodic structures with optimal number of overlapping gratings result in more than 10 dB emission suppression. We show this significant emission suppression for refractive-indices of 1.38, 1.43 and 1.58 by numerical simulations.

Due to the growing market for Micro Electro Mechanical Systems (MEMS), especially for the application in mobile electronic devices like cameras, phones or tablet computers, cost and time efficient test and evaluation systems are required for the production process. This work presents a novel measurement setup for MEMS microphones, that allows an inline, contactless evaluation of the microphones' mechanical sensitivity at an early stage of the manufacturing process. A heterodyne receiver with a Six-port demodulator is deployed for displacement detection with micrometer resolution. Since the Six-port demodulator allows very high sampling rates, only limited by the analog-to-digital converter, short measurement times can be achieved.

A successive approximation ADC based on the C2C DAC architecture is introduced. The ADC designed in a 0.18μm CMOS 2 Poly 4 Metal process uses a hybrid capacitive DAC combining the best of the binary weighted capacitive array and the C2C array. C2C ladder based architectures are very attractive for implementation because of its small area, high speed and low power consumption. However a major drawback associated with this DAC is the presence of high parasitic bottom plate capacitances. A concept called the floating voltage shield (FVS) is introduced to reduce the effect of these parasitic capacitances and maximize the effective use of the C2C DAC features. The converter consists of the hybrid DAC, a two stage preamplifier followed by a dynamic latch, switch array and digital circuitry for switching and control. The ADC consumes a maximum power of 630μW at a peak conversion rate of approximately 2MS/s from a 1.8V supply voltage and 40MHz clock. Use of extremely simple and yet robust analog architectures for the comparator make the ADC operation less prone to process variation errors. © 2009 IEEE.

This paper describes the design and characterization of three different compact low-cost substrate integrated waveguide (SIW) leaky-wave antennas on a RO4350B substrate. In order to increase the gain of the basic leaky-wave antenna, two different arrays consisting of multiple parallel fed SIW lines are formed. Measurements of both return loss and radiation pattern were performed for all three antenna structures around 122.5GHz and show good agreement with the numerical results. The maximum realized gain has been determined to be slightly above 16dBi.

A mixed-signal chip in 130nm Technology is described. The chip acquires EMG signals from five differential inputs. The signals are amplified, multiplexed and digitized inside the developed chip. The ASIC is optimised for low power and low noise and is intended for application in medical implants. Furthermore, the chip provides a configuration options for several parameters for the analogue part of the chip. The chip has been tested by recording EMG signals from implanted Myo-Electrodes.

In this work we present a programmable 1.2 V Operational Amplifier (OpAmp) realized in a standard 130 nm CMOS technology. The OpAmp is based on a 3 V rail-to-rail input/output topology. The experimental results show the feasibility of using higher voltage topologies in conjunction with multi-threshold (multi-Vth) process options for low voltage designs. The programming range extends from a low-noise to a low-power mode. In addition, a constant-gm stage has been added to the rail-to-rail input. In low-noise mode the OpAmp has a low input thermal noise voltage of 5.1 nV/√Hz and in lowpower mode a power consumption of only 203 μW. Over the whole programming range the OpAmp maintains unity-gain stability with its phase margin varying between 58° and 62° © 2008 IEEE.

The experimental setup of a gyrotron which operates in the TE0,3 mode is described. The results of measurements with several gyrotron versions at short pulses (0.5 ms) and long pulses (100 ms) are reported. Designs for higher powers (up to 1 MW) using a nonsymmetric volume mode are presented. First experiments will use the TE10,4 mode. A quasioptical convertor for the output mode will be used, either in conjunction with an axial window or, later, with a radial window.

The brain has only limited ability to deal with complex Problems. Therefore, the developer must be supported to supplement his natural problem-solving behaviors. The SPALTEN-Methodology was described by Albers et al. and constantly developed further in the past 15 years. Furthermore, it was applied consistently in projects and education. SPALTEN is a German acronym and means "to split", "to decompose". In this contribution, the results of an extensive empirical study of the use of SPALTEN in the last 15 years is presented. The study consists of a qualitative preliminary study on basic of interviews (n=15) and a quantitative survey using a questionnaire (n=108) and has a focus on the application and the added value for the user. The results show, that SPALTEN is used in practice by over 80 % of former students and PhD-students, who learned the method in their education.

The teaching program IP - Integrated Product Development has been implemented annually with great success for 20 years, which means that this format has gained a high level of acceptance among companies from a wide range of industries. The participating students acquire professional skills in the area of PGE - Product Generation Engineering through the experience of the real development project and by applying activities and methods of product development, combined with a lecture that deals with the most recent cases from the business world. With the aim of bringing the co-creation formats to further student target groups with diverse needs, the format IP was analyzed and a general valid co-creation approach for case-based learning, was characterized by relevant success factors. Based on this, it was possible to transfer the success factors from IP contextual into the breadth (reaching a high number of students) and into the depth (gain of research competences) by means of two further formats.

For numerous medical applications it is of primary interest to monitor the breath rate and heartbeat of a patient over time. Especially important is to observe the respiration of a patient over night to detect potential sleep disorders. Furthermore, heartbeat frequency is also a precious information which can help to improve diverse diagnosis procedures. In order to better analyze these vital parameters an innovative contactless respiration detection and heartbeat monitoring technique has been developed. This novel method is based on the six-port interferometric radar and is capable of detecting breath rate as well as heartbeat frequency without applying sensors or electrodes on the patients body.

We introduce a 2D waveguide platform employing an integrating cell approach which enables ultra-long optical propagation paths in a very small geometrical footprint. Effective propagation length of 25 cm is demonstrated.

A 2D integrating cell waveguide platform is presented where ultra-long optical path lengths in a small area are realized by multiple reflections of a guided signal at PhC boundaries. In experiments, path lengths of 25 cm are demonstrated in integrating cells with 1.8 mm radius.

A high voltage (HV) that is usually not available in modern nodes is required to form memristors. A scalable implementation requires the HV to be generated on chip and this work proposes such a generator. In a 28 nm CMOS process, a three-stage charge pump (CP)) is designed in the absence of HV transistors. For the HfO2 based memristor electroforming (EF), a developed CP runs with an efficiency of 46.5% at an output voltage of 3.35 V and a load current of 184.9 μ A from a 1.8 V supply. The optimum design strategy for a cross-coupled charge pump (CC-CP) is explained for a low ripple <6 mV, while at the same time ensuring lower capacitor value and high reliability. The results of an over-voltage analytical investigation have important ramifications for lowering the overall area without compromising output voltage or CP efficiency. Monte Carlo simulation for 200 samples were also performed to verify the design's robustness. However, the proposed design can be readily extended to any memristor application or material, thereby paving the way for the integration of fully integrated chips (ICs) for memristor EF in smaller technology nodes.

We present a new (3/2+1/e)-approximation algorithm for the Ordered Traveling Salesperson Problem (Ordered TSP). Ordered TSP is a variant of the classic metric Traveling Salesperson Problem (TSP) where a specified subset of vertices needs to appear on the output Hamiltonian cycle in a given order, and the task is to compute a cheapest such cycle. Our approximation guarantee of approximately 1.868 holds with respect to the value of a natural new linear programming (LP) relaxation for Ordered TSP. Our result significantly improves upon the previously best known guarantee of 5/2 for this problem and thereby considerably reduces the gap between approximability of Ordered TSP and metric TSP. Our algorithm is based on a decomposition of the LP solution into weighted trees that serve as building blocks in our tour construction.

One of the most studied extensions of the famous Traveling Salesperson Problem (TSP) is the Multiple TSP: a set of m ≥ 1 salespersons collectively traverses a set of n cities by m non-trivial tours, to minimize the total length of their tours. This problem can also be considered to be a variant of Uncapacitated Vehicle Routing, where the objective is to minimize the sum of all tour lengths. When all m tours start from and end at a single common depot v0, then the metric Multiple TSP can be approximated equally well as the standard metric TSP, as shown by Frieze (1983). The metric Multiple TSP becomes significantly harder to approximate when there is a set D of d ≥ 1 depots that form the starting and end points of the m tours. For this case, only a (2 − 1/d)-approximation in polynomial time is known, as well as a 3/2-approximation for constant d which requires a prohibitive run time of n^Θ(d) (Xu and Rodrigues, INFORMS J. Comput., 2015). A recent work of Traub, Vygen and Zenklusen (STOC 2020) gives another approximation algorithm for metric Multiple TSP with run time n^Θ(d), which reduces the problem to approximating metric TSP. In this paper we overcome the n^Θ(d) time barrier: we give the first efficient approximation algorithm for Multiple TSP with a variable number d of depots that yields a better-than-2 approximation. Our algorithm runs in time (1/ε)^O(d log d)· n^O(1), and produces a (3/2 + ε)-approximation with constant probability. For the graphic case, we obtain a deterministic 3/2-approximation in time 2^d· n^O(1).