Highly integrated multilayered printed circuit board-based patch antenna arrays are proposed in this study for 60 GHz wireless communications. Electromagnetic coupling between two stacked patches is used to achieve the broadband performance. Different structures of single element antennas, two-element antenna arrays and four-element antenna arrays are presented. The two compact four-element antenna arrays show < -10 dB impedance bandwidth of 13 and 14.6% with 12 dBi peak gain. The arrays have the 3 dB gain bandwidth of 9 and 13%. A single column, four-element sub-array is used to design 4 x 16 antenna array. This array delivers 20.8 dBi peak gain with 13% impedance and gain bandwidth. Furthermore, a two-element series fed array is used to realise a 2 x 16 phased antenna array. This array is fed through a 16 x channel radio frequency IC to achieve the beam steering in +/- 50 degrees range.

The continued growth in mobile data traffic is pushing for new and innovative solutions. Over the next few years, cellular phones, tablets, and computers will switch to 5G wireless technology. In this work, an highly integrated WiGig/802.11ad compliant 16+16 beam forming transceiver RFIC with advanced FOWLP (fan out wafer level packaging) technology known as eWLB (embedded wafer level BGA) is presented, which supports the need for the increased demand of data traffic. The 0.5mm pitch eWLB package measures 12.6x12.6x0.8mm and is using advanced dielectric materials and 2 metal layers for the redistribution layers (RDL). Full-wave electromagnetic simulations were performed including models of the chip layout, interconnects on the RDL, transitions and PCB. JEDEC level reliability was tested for component level reliability including MSL, TC, uHAST and HTS. The measurement results of compressed output power and noise figure for both bare die and packaged chip are presented.

This paper presents a 60 GHz connected slots linear phased array feeding a high gain semi-symmetric lens antenna. This novel design provides high gain, broadband and beam-steering capabilities for gigabits rate access and backhaul communications. The 16× connected slots are fed periodically to allow ± 45 ° beam-steering in the H-plane. The results show more than 33% impedance bandwidth, 24.6 dBi maximum gain and 3 dB gain bandwidth covering the full band 57-66 GHz. Besides, the half power beamwidth (HPBW) is 6° and 10° in E-and H-plane, respectively.

Highly integrated multilayered patch antenna arrays are proposed in this paper for 60 GHz wireless communications. Electromagnetic coupling between two stacked patches is used for improving the broadband performance. Three different structures of single column 4-element arrays are presented with center and corporate feeding networks. Maximum gain of 12.2 dBi and <-10 dB return loss in the entire unlicensed frequency band 57–66 GHz is measured. Furthermore, a compact 4×16 antenna array (41 mm × 13 mm) is presented with 18.7 dBi maximum gain, 8 GHz (57–65) bandwidth and 7° HPBW (half power beam width) in H plane.

A beamforming transceiver for 802.11ad-based wireless access applications manufactured in a f(T)/f(max) = 250/340-GHz SiGe BiCMOS technology is presented. The transceiver is equipped with 16+16 separate RX/TX paths and provides more than 20 dBm combined output power and 6 dB NF in the standard 802.11ad 57-66 GHz band, as well as the 66-to-71-GHz extended fixed-wireless access frequency range. A low phase noise of -101 dBc at 1 MHz offset enables the use of up to 10 Gbit/s 128 QAM full-channel and 256 QAM half-channel single-carrier modulation.

This paper presents a compact varactor grid frequency doubler encapsulated in a waveguide environment, thus providing single mode (H-10) waveguide connection at both input and output. Schottky diodes are used as varactors in this 128-element grid frequency doubler. By packaging the grid and its embedding network together with a stepped waveguide taper on the output, a module measuring 9 mm x 19 mm by 19 mm is created. A peak output power of 0.25 W is produced at 183 GHz with 1.32 W of input power and a corresponding conversion efficiency of 19%. The peak conversion efficiency is 23% at 183 GHz with 666 mW of input power.

We present a full wave, large-signal analysis of a waveguide-embedded frequency multiplier array, solving the entire geometry using FEM EM modeling and including every nonlinear element in a Harmonic Balance simulation. The full 3D model employed provides the exact field distribution across the array, thus enabling us to account for substrate resonances, higher order mode excitation, instabilities, and diode yield. The model is compared with measurements on a 247 GHz fixed tuned 72-diode HBV tripler. In this example, higher order mode excitation was found due to the interaction between the filter and the diode array. This can only be observed using a full 3D model, which more accurately predicts the output power versus input power and frequency. Finally, the pros and cons of a full 3D model and a unit cell model for waveguide embedded multiplier arrays are discussed.

We present a solution where one single LO chain is used to feed a homodyne FMCW radar transceiver. An InGaAs pHEMT active frequency multiplier MMIC (x8) and a Schottky diode frequency doubler make up the LO chain. The novel Schottky diode based transceiver operates both as a frequency multiplier (x2) and as a sub-harmonic mixer.The modules operate at a center frequency of 340 GHz with a 30 GHz modulation bandwidth. An output power of 0 dBm, an IF noise level of -168 dBm/Hz and a receiver conversion loss of 18 dB is achieved in the band. The form factor of the modules is adapted to build one-or two-dimensional FMCW radar arrays. State of the art system performance is achieved while system complexity, size and cost is significantly reduced.

This paper presents a high-power 240-290 GHz wave-guide enclosed two-dimensional (2-D) grid heterostructure barrier varactor (HBV) frequency multiplier. A 35 mW of output power is produced at 247 GHz with an input power of 900 mW. The operational bandwidth is tunable within a 50 GHz span by the use of an input tuner able to adjust the input matching of the 2-D grid HBV frequency multiplier. Tuning is achieved by moving a suspended dielectric slab in the input waveguide.

In this paper, measurements with a THz imaging system at 346 GHz together with electromagnetic simulations have demonstrated the capability of THz sensing for the non-destructive density determination of intermediate products in the pharmaceutical industry. The results confirm the ability of THz imaging to detect density changes in pharmaceutical samples by measuring the phase variation of the wave transmitted through the sample.

This work reports on a 248 GHz HBV (Heterostructure Barrier Varactors)-varactor quasi-optical multiplier array with a maximum output power of 18 mW and a corresponding conversion efficiency of 2 %. The module utilizes a mechanically compact and simple shim system, combining the large array power handling capability with the convenience of waveguide interfaced circuits. At the same time this approach offers excellent power and frequency scalability. The multiplier is based on a 12 by 6 element, 72 in total, planar 2D HBV varactor array. The diodes are fabricated on a three barrier InGaAs/InAlAs material system on InP as carrier substrate. Easch diode consist of two 20um^2 serially connected mesas, yielding a total of six barrier per diode. The HBV diodes are coupled to a uniform dipole array through which the power is coupled in and out. One HBV diode and the corresponding dipole make up a square unit cell with a side of 211 um. The chip measures 2,54 x 1,27 mm^2, fitting inside a standard WR10 waveguide. The complete module consists of three parts, the 2D HBV array, a combined output filter and output matching slab and an input matching slab. A rhombic aperture frequency selective surface is used as the uutput bandpass filter and the quartz filter substrate also serves as a matching slab for the output tone. On the input a piece of InP substrate is used to match the incoming pump signal to the diodes. The components are mounted inside two WR-10 waveguide shims, providing an easy assembly and a modular system. The current version of the multiplier module produces 18 mW at 248 GHz but a significant increase in output power and efficiency is expected with a new output matching network and more pump power. Recent measurement results will be presented together with a detailed discussion regarding the design, pointing out advantages and challenges compared to more traditional approaches to frequency multiplier design in the frequency range. Future improvements and challenges will also be covered.

The utilisation of the THz spectrum ( 0.3-3 THz ) is hampered by technological difficulties to generate power at these frequencies. Applications within diverse fields such as radio astronomy, security imaging, life sciences, high data rate communications and production monitoring could benefit significantly from compact, high power THz signal sources operating at room temperature. This thesis reports on the design and fabrication aspects of varactor diode based 2D array frequency multipliers. Both free space operating and waveguide en- closed Heterostructure Barrier Varactors (HBVs) arrays are discussed in detail. The goal of this work has been to design, fabricate and characterise high power varactor 2D array frequency multipliers, enabling increased power handling capabilities and output power of future THz frequency multipliers. This approach is expected to offer excellent frequency and power scalability for THz signal sources. An altogether waveguide integrated 249 GHz HBV 2D array frequency tripler is presented together with measurement data. With an output power of 18 mW at 248 GHz and a conversion efficiency of 2 %, this is the highest frequency of operation and output power reported to date for waveguide enclosed 2D array frequency multipliers. A 346 GHz imaging system is also presented as an application example for powerful THz signal sources. The system uses an imaging algorithm based on the Born approximation and produces images with a voxel size of 0.1 × 0.1 mm2 (approximately 1/10 of the free space wavelength).

A waveguide embedded 250 GHz HBV-varactor quasi-optical multiplier array is presented. The module utilizes a mechanically compact and simple shim system, combining the large array power handling capability with the convenience of waveguide interfaced circuits. At the same time this approach offers excellent power and frequency scalability. The current tripler prototype produces a non saturated output power of 8 mW at 248 GHz during initial measurements at medium pump power.

We present the development of integrated submillimeter wave receivers and transmitters based on Schottky- and HBV-diode technology at Chalmers University of technology.

A THz imaging system, operating at 346 GHz and tailored for implementation of an imaging algorithm based on the Born approximation, is presented. The imaging algorithm provides focusing by compensating for the antenna footprint. This allows for using a more simple antenna system without optical focusing. Several aspects of implementing an imaging algorithm based on the Born approximation in THz imaging are discussed and key system properties are highlighted. The performance of the imaging algorithm is verified by imaging two simple dielectric targets. The results indicate that this approach provides a qualitative indication of the distribution of contrast in the samples complex permittivity and is a potential complement to existing imaging techniques.