No abstract

Advantages of the lensless Fourier holography setup for the reconstruction of digitally recorded holograms in holographic interferometry are presented. This very simple setup helps to achieve a maximum lateral resolution of the object under investigation. Also, the numerical-reconstruction algorithm is very simple and fast to compute. A mathematical model based on Fourier optics is used to describe discretization effects and to determine the lateral resolution. The recording and the reconstruction processes are regarded as an optical imaging system, and the point-spread function is calculated. Results are verified by an experimental setup for a combined shape and deformation measurement.

No abstract

The embedded wafer level ball grid array (eWLB) is a novel packaging technology that shows excellent performance for millimeter-wave (mm-wave) applications. We present simulation and measurement results of single-ended and differential transmission lines realized using the thin-film redistribution layers (RDL) of an eWLB. We demonstrate the capabilities for the integration of passives on example of a configurable 17/18 GHz down-converter circuit realized in silicongermanium (SiGe) technology with a fan-in eWLB differential inductor used for the LC tank. We compare the performance of differential chip-package-board transitions realized in an eWLB and in other common package types. We report an optimized compact chip-package-board transition in the eWLB. We obtain a simulated insertion loss as low as −0.65 dB and a return loss below −16 dB at 77 GHz without external matching networks. We introduce the concept of antenna integration in the eWLB and show examples of single-ended and differential antenna structures. Finally, we present for the first time a single-chip four-channel 77 GHz transceiver in SiGe integrated in the eWLB package together with four dipole antennas. The presented examples demonstrate that the eWLB technology is an attractive candidate for mm-wave applications including system-in-package (SiP). IntroductionNear field communication or wireless local and personal networking (WLAN, WPAN) at 60 GHz, adaptive cruise control (ACC) radar at 77 GHz, or high-resolution radio imaging at 94 GHz and 140 GHz are only a few examples of applications for upcoming future markets [1]. The size of a package becomes comparable to a wavelength at mm-wave frequencies. The parasitic wave effects such as impedance mismatch, signal reflections, crosstalk, and radiation can no longer be neglected even for very small chip-scale packages. This leads to large discontinuities at the chip/package and package/board interfaces that must be optimized. Moreover, the small wavelength at mm-wave frequencies demands high-precision fabrication. Even small variations due to process tolerances can have a significant impact on the end-product performance. The use of traditional packages is therefore limited at mmwave frequencies.The embedded wafer level ball grid array (eWLB) technology is a new assembly and packaging technology that offers attractive possibilities for mm-wave systems. The length of interconnections in the redistribution layer (RDL) is very short. This results in reduced parasitics and excellent electrical performance up to mm-wave frequencies. Moreover, excellent electrical properties of the materials and a high metal-pattern

A phased array antenna, used for shaping and steering the main antenna beam electronically to chosen directions within the predefined field of view, has been the key antenna system for satellite communications and military radars for decades. However, despite its high functional performance, it is still a very costly and complex solution for emerging wireless consumer applications such as high speed wireless communication and driving assistance systems due to the number of phase shifters and their complex control circuitry. Even more challenges are encountered with an increase in the number of channels if an antenna with high directivity is desired, such as routing RF and IF circuits, isolation of neighboring RF channels or calibration of a whole system.In order to eliminate the challenges stated above, a novel beam steering approach is presented in this dissertation based on the superposition of two squinted antenna beams. The two antenna beams are realized by exciting the opposite feeds of a dual-fed array antenna. A change in the phase difference and amplitude ratio between the input signals, using only one phase shifter and two variable gain amplifiers or only two I-Q vector modulators, steers the main beam in different directions. Due to its similar architecture, it exhibits all the advantages that a traveling wave antenna possesses as well, such as beam steering with the change of the operating frequency.Additionally, the sum and difference patterns can be obtained using this concept, allowing for an amplitude-comparison monopulse operation with a broad peak or a deep null at the broadside. Using this approach, beam nulls can also be steered towards interference directions, while keeping the shape and direction of the main beam unchanged. Another advantage is its high robustness against phase and amplitude errors due to analog hardware components in the RF path, which cannot be avoided in conventional phased arrays. A channel mismatch and crosstalk between neighbor RF channels or a temperature and time dependent array calibration can be minimized via this technique thanks to its unique topology, as well.In this work, an analytic antenna model has been derived and implemented in MATLAB using closed form expressions to analyze and optimize each relevant antenna parameter. Using this model, the development time becomes significantly shorter and the required computer memory is almost negligible.In order to prove the validity of the proposed novel beam steering approach, two different millimeter-wave (mm-wave) dual-feed antenna setups have been designed and implemented. In the first setup, commercial passive WR-10 components are used to perform the phase and i -iiamplitude changes manually. To demonstrate the full capability of electronic scanning, a second setup is built by employing an I-Q vector modulator instead of the waveguide phase shifter and the attenuator, which is controllable via input current signals. A mm-wave baredie transceiver MMIC which houses an integrated I-Q vector modulator in its ...