Antti Lamminen

60-GHz Patch Antennas and Arrays on LTCC With Embedded-Cavity Substrates

The design is presented of aperture-coupled microstrip line-fed patch antennas (ACMPAs) and 4times4 planar arrays on Ferro A6-S low-temperature cofired ceramic (LTCC) substrate operating in the 60-GHz frequency band. In addition to the traditional ACMPA design, air cavities processed inside the LTCC substrate are used to improve the bandwidth and gain of the antennas. The arrays are excited through the microstrip-line feed networks using quarter-wave matched T-junctions and using Wilkinson power dividers. The results show that ACMPAs and arrays can be fabricated with a standard LTCC process even for the millimeter-wave region. Good agreement is achieved between simulations and measurements. The measured S-parameters indicate impedance bandwidths of 9.5% and 5.8% for the array elements with and without an embedded cavity. The measured maximum gains for the 16-element patch arrays (with and without cavity) are 18.2 and 15.7 dBi, respectively.

UC-EBG on LTCC for 60-GHz Frequency Band Antenna Applications

The relatively high dielectric constant of the low-temperature cofired ceramic (LTCC) substrate materials can reduce the antenna gain and increase the mutual coupling in antenna arrays due to the increased surface-wave power. We present a design of a uniplanar-compact electromagnetic band-gap (UC-EBG) structure on the Ferro A6-S LTCC tape system operating in the 60-GHz frequency band. The UC-EBG design is used with an aperture-coupled microstrip-line-fed patch antenna (ACMPA) and with a 16-element array to increase the antenna gain. The UC-EBG is also used to reduce the mutual coupling between antennas in the E- and H-planes. The performance of the antennas with and without UC-EBG are evaluated with the probe-station and radiation-pattern measurements. In addition, the reflection from the UC-EBG surface is measured using a WR-15 waveguide excitation. Good agreement is achieved between the simulations and the measurements. An increase of up to 4.5 and 2.3 dBi is achieved in the gain for a single element and for a 16-element array, respectively. A reduction of up to 11.8 dB is observed in the E-plane coupling between two patches. The presented design is suitable for electromagnetic shielding, reduction of coupling in integrated LTCC modules, and providing high gain antennas for low-cost millimeter-wave applications.

60-GHz Millimeter-Wave Identification Reader on 90-nm CMOS and LTCC

A reader module at 60 GHz for high data-rate short-range backscattering-based communications is presented. The reader consists of a CMOS-based oscillator, amplifiers, and a mixer on a low-temperature co-fired ceramic (LTCC) substrate. The filter, power splitter, and antennas are directly patterned on the LTCC. All millimeter-wave components are contained within the module and the only interfaces to the module are the IF and bias lines. Transmit power of the module is +11.6-dBm effective isotropic radiated power with an IF bandwidth of 400 MHz. The LTCC module measures 13×24 mm2 and has a dc power consumption of 130 mW. Reception of a 20-MHz square wave from a tag 5 cm apart from the reader is demonstrated; the suggested millimeter-wave identification concept enables a 102- 103-fold data-rate increase in comparison to the present near-field communication technique, with similar size, range, and power consumption of the reader.

2-D Beam-Steerable Integrated Lens Antenna System for 5G

The new services available through smart devices require very high cellular network capacity. The capacity requirement is expected to increase exponentially with the forthcoming 5G networks. The only available spectrum for truly wideband communication (>1 GHz) is at millimeter wavelengths. The high free space loss can be overcome by using the directive and beam-steerable antennas. This paper describes a design and the measurement results for a lens antenna system for E-band having 2-D beam-steering capability. Continuous beam-switching range of about ±4° × ±17° is demonstrated with the lens having the maximum measured directivity of 36.7 dB. Link budget calculation for backhaul application using the presented lens antenna system is presented and compared with the measurement results of the implemented demo system.

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Technical solutions for automotive intermodulation radar for detecting vulnerable road users

-Band Access and Backhaul

This paper shows that it is possible to make functional probe-fed patch antennas on low-temperature co-fired ceramic (LTCC) substrates for 60 GHz. The designed antennas were realised on a 0.5-mm-thick LTCC substrate using a commercial Ferro A6-S LTCC material system. According to the measurements, a stacked square two-element patch antenna had 2.7 GHz and a circular single-element patch antenna had up to 6 GHz of the -10-dB-return-loss bandwidth. The manufacturing tolerances caused some de-tuning of the resonance frequency, plusmn1 GHz. The measured maximum radiation gain of the circular antenna was 5.9 dBi at 57 GHz

Technical Solutions for Automotive Intermodulation Radar for Detecting Vulnerable Road Users

We have studied beam-steering radio in the E-band., e.g. for high-capacity communication links. Lens antennas provide high gain and are suitable for integration at millimeter wave frequencies, e.g., for beam-switching a planar antenna array with a switching network may be integrated to the surface of the lens; one patch is activated at a time for each beam direction. In order to improve the scanning characteristics and reduce reflection losses, we have studied optimization of the lens shape using ray tracing. A propagation channel model has been developed for point-to-point links in street canyons and from roof to street in an urban environment. The model is based on extensive measurements in the E-band. The substance of the channel model is in identification of multipath components in the environment. That is supported by separate measurements of radio wave reflection and scattering from various environmental structures such as building walls.

Design and Measurements of 60 GHz Probe-fed Patch Antennas on Low-Temperature Co-Fired Ceramic Substrates

A V-band, switched-beam, linearly polarized transmit-array antenna enabling self-pointing point-to-point communication systems, e.g., wireless backhaul applications in the future mobile networks, is presented. The antenna is designed and fabricated using standard printed-circuit board materials and processes as well as commercially available switches. The design and characterization of the unit cells and the transmit-array panel are presented and demonstrate state-of-the-art performances with an experimental realized gain of 33.4 dBi, an aperture efficiency of 48%, and a 3-dB bandwidth of 15.4%. Furthermore, the transmit array fed by the focal array is presented and demonstrates radiation properties and beam-switching capabilities with five beams at 0°, ±2.4°, and ±4.8°, and a 3-dB angular coverage of 13.2°.

Studies on E-band antennas and propagation

We present a flat switched-beam antenna that achieves a wide angular coverage (±38°) and limited scan losses in V-band. The system features two broadband continuous transverse stub (CTS) arrays, each fed by a pillbox beamformer. The two antennas are designed so that the radiated beams are interleaved. In this way, high beam overlap levels (–3 dB) and low side lobe level are simultaneously attained. A switch network excites one of the two apertures at a time and selects the desired beam. The system is fully integrated in a low-profile multilayer low temperature co-fired ceramic (LTCC) module. The proposed architecture and technology are suitable for millimeter-wave access points in next generation mobile networks.

A V-Band Switched-Beam Linearly Polarized Transmit-Array Antenna for Wireless Backhaul Applications

This paper presents the design of a 90 GHz phased-array transmitter front end on low-temperature co-fired ceramic (LTCC) technology. The monolithic microwave integrated circuit components have been fabricated by the CMOS technology and flip chipped on the LTCC to realize the transmitter front end. The dc and differential hybrid IF signals are provided to the flip-chipped components through the bias and IF lines designed on the LTCC. An