This paper presents a power amplifier (PA) designed as a part of a transceiver front-end fabricated in 130-nm SiGe BiCMOS. The PA shares its output antenna port with a low noise amplifier using a low-loss transmission/reception switch. The output matching network of the PA is designed to provide high output power, low AM-AM distortion, and uniform performance over frequencies in the range of 24.25-29.5GHz. Measurements of the front-end in TX mode demonstrate peak S21 of 30.3dB at 26.7GHz, S21 3-dB bandwidth of 9.8GHz from 22.2to 32.0GHz, and saturated output power (Psat) above 20dBm with power-added efficiency (PAE) above 22% from 24 to 30GHz. For a 64-QAM 400MHz bandwidth orthogonal frequency division multiplexing (OFDM) signal, -25dBc error vector magnitude (EVM) is measured at an average output power of 12.3dBm and average PAE of 8.8%. The PA achieves a competitive ITRS FoM of 92.9.

Capacitive coupling of line coded and DC-balanced digital signals is often used to eliminate steady bias current flow between the systems or components in various communication systems. A multi-layer ceramic chip capacitor is promising for the capacitor of very broadband signal coupling because of its high frequency characteristics expected from the downsizing of the chip recent years. The lower limit of the coupling bandwidth is determined by the capacitance while the higher limit is affected by the parasitic inductance associated with the chip structure. In this paper, we investigate the coupling characteristics up to millimeter wave frequencies by the measurement and simulations. A phenomenon has been found in which the change in the current distribution in the chip structure occur at high frequencies and the coupling characteristics are improved compared to the prediction based on the conventional equivalent circuit model. A new equivalent circuit model of chip capacitor that can express the effect of the improvement has been proposed.

In this paper, two receive beamforming techniques (Method 1 and Method 2) are proposed for a mobile station (MS) with multiple antenna arrays in an OFDM-based millimeter-wave (mm-wave) cellular communication system. Since the MS in mm-wave cellular communication requires fast processing due to its frequent movement and rotation, a receive beamforming technique with reduced computation complexity and processing time is proposed in Method 2. Of particular interest, estimation techniques for 2-dimensional (2D) direction-of-arrivals (DoAs) corresponding to each cell ID are proposed for uniform circular arrays (UCAs) and uniform rectangular arrays (URAs). Also, a cell selection technique for MSs with multiple antenna arrays is described that use the candidate cell IDs and parameters estimated for all antenna arrays to provide combining gain in addition to array gain in multipath channels. The proposed beamforming techniques are evaluated by computer simulation using a simple model of amm-wave cellular communication system with 3-dimensional spatial channel model (3D SCM).

As new systems and applications are introduced for next-generation wireless systems, the propagation channels in which they operate need to be characterized. This paper discusses propagation channels for four types of next-generation systems: (i) distributed Multiple-Input Multiple-Output (MIMO) and Cooperative MultiPoint (CoMP) systems, which require the characterization of correlation between channels from a mobile station to different base stations or access points; (ii) device-to-device communications, where propagation channels are characterized by strong mobility at both link ends (e.g., in vehicle-to-vehicle communications), and/or significant impact of moving shadowing objects; (iii) full-dimensional MIMO, where antenna arrays extend in both the horizontal and vertical dimension, so that azimuthal and elevation dispersion characteristics of the channel become relevant, and (iv) millimeter wave Wireless Local Area Network (WLAN) and cellular communication systems, where the high carrier frequency leads to a change (compared to microwave communications) concerning which propagation processes are dominant. For each of these areas, we give an overview of measurements and models for key channel properties. A discussion of open issues and possible future research avenues is also provided.

At mm-wave frequency, the layout of CMOS transistors has a larger effect on the device performance than ever before in low frequency. In this work, the distance between the gate and drain contact (Dgd) has been enlarged to obtain a better maximum available gain (MAG). By using the asymmetric-layout transistor, a 0.6 dB MAG improvement is realized when Dgd changes from 60 nm to 200 nm. A four-stage common-source low noise amplifier is implemented in a 65 nm CMOS process. A measured peak power gain of 24 dB is achieved with a power dissipation of 30 mW from a 1.2-V power supply. An 18 dB variable gain is also realized by adjusting the bias voltage. The measured 3-dB bandwidth is about 17 GHz from 51 GHz to 68 GHz, and noise figure (NF) is from 4.0 dB to 7.6 dB.

The noise performance of common source and cascode topology 60 GHz LNAs is analyzed and verified. The analysis result shows that the noise performance of the cascode topology is degraded at high frequency due to the inter-stage node capacitance. The analysis result is verified by experimental results. A three-stage LNA employing two noise-matched CS stages and a cascode stage is proposed. For comparison a conventional two-stage cascode LNA is also been studied with the measurement-based model. The measured results of the proposed LNA show that an input and output matching of less than -10 dB, a maximum gain of 9.7 dB and a noise figure (NF) of 3.2 dB are obtained with a power consumption of 30 mW from a 1.2-V supply voltage. Compared to the conventional cascode LNA, an improvement of 2.3-dB for NF and 1.9-dB for power gain are realized. Both the proposed and conventional LNAs are implemented in 65 nm CMOS process.

In this work, a V-band low noise amplifier (LNA) is developed in a commercial 0.13 µm RFCMOS technology. Common-source (CS) topology, known to show a better noise performance than the cascode topology, was adopted and 4-stage was employed to achieve a sufficient gain at the target frequency near the cutoff frequency fT. The measured gain was 18.6 dB with VDD = 1.2 V and increased up to 20.2 dB with VDD = 1.8 V at 66 GHz. The measured NF showed a minimum value of 7.0 dB at 62 GHz. DC power consumption was 24 mW with VDD = 1.2 V. The size of the fabricated circuit is as compact as 0.45 mm 0.69 mm. This work was further extended to investigate the effect of dummy fills on LNA performance. An identical LNA, except for the dummy fills formed very close to (and under) the metal lines of spiral inductors and interconnects, was also fabricated and compared with the standard LNA. A peak gain degradation of 3.6 dB and average NF degradation of 1.3 dB were observed, which can be ascribed to the increased mismatch and line loss due to the dummy fills.

A new design and experimental results of a microstrip-fed ultra-wideband Fermi antenna at millimeter-wave frequencies are presented. By utilizing a new microstrip-to-CPS balun (or transition), which provides wider bandwidth than conventional planar balun, the design of microstrip-fed Fermi antenna is greatly simplified. The proposed Fermi antenna demonstrates ultra-wideband performance for the frequency range of 23 to over 58 GHz with the antenna gain of 12 to 14 dBi and low sidelobe levels. This design yields highly effective solutions to various millimeter-wave phased-arrays and imaging systems.

This paper proposes a de-embedding method for on-chip S-parameter measurements at mm-wave frequency. The proposed method uses only two transmission lines with different length. In the proposed method, a parasitic-component model extracted from two transmission lines can be used for de-embedding for other-type DUTs like transistor, capacitor, inductor, etc. The experimental results show that the error in characteristic impedance between the different-length transmission lines is less than 0.7% above 40 GHz. The extracted pad model is also shown.

Bessel beams are a family of diffraction-free beams. They have many unique properties and prospective applications. Much attention has been focused to this subject in optics. Recently, the studies of such beams at mm- and submm- wavebands have been carried out in our group. The investigation results, including their theories, generation, propagation and potential applications, are presented in this paper.

This paper highlights seven years of research at the Berkeley Wireless Research Center (BWRC) related to mm-wave electronics. Active and passive device design and layout, circuit approaches, and system architecture for short range mm-wave communication links will be discussed. The design of several key building blocks in a receiver front-end will be highlighted.

Millimeter-waves integrated circuits offer a unique opportunity for a holistic design approach encompassing RF, analog, and digital, as well as radiation and electromagnetics. The ability to deal with the complete system covering a broad range from the digital circuitry to on-chip antennas and everything in between offers unparalleled opportunities for completely new architectures and topologies, which were previously impossible due the traditional partitioning of various blocks in conventional design. This can open a plethora of new architectural and system level innovation within the integrated circuit platform. This paper reviews some of the challenges and opportunities for mm-wave ICs and presents several solutions to them.

This paper proposes an improved nonlinear FET model along with its parameter extraction procedure suitable for the accurate prediction of inter-modulation product's levels (IM) and spurious responses in active and passive applications. This new model allows accurate capture of the drain current behavior and its derivatives with respect to the gate voltage and the drain voltage in the both the saturated and linear regions of the I-V biasing domain. It was found that this model accurately predicts the bias-dependent S-parameters as well as IM's levels for both amplifier and mixer applications up to mm-wave frequencies.

Problems of flipped-chip MMIC at millimeter-wave frequency are investigated. Practical design criteria are introduced to obtain resonance and cutoff frequency for parasitic mode with flipped-chip MMIC structure. We investigate the advantages and disadvantages of three types of transmission line for flipped-chip MMIC in both electromagnetic simulation and scale-model. To avoid the resonance in coplanar waveguide flipped-chip MMIC new bridge structure is proposed.

A new electromagnetic coupling structure has been proposed for a millimeter wave DR-VCO. The structure consists of a microstrip substrate placed on a planar type dielectric resonator and provides a strongly confined electromagnetic field and a high Q. The resonator used in this structure is a TE010 mode dielectric resonator composed of a dielectric substrate and electrodes on both sides of the substrate. Each electrode has a circular hollow patch. A microstrip circuit substrate with an aperture on the ground electrode is stacked on the resonator. The resonator is magnetically coupled to the transmission line through the aperture. The coupling structure has advantages as follows: (a) The electromagnetic field is strongly confined at the hollow patch, and (b) unloaded Q reduction is only 18% under a strong coupling. When the structure is used as a resonant circuit for a DR-VCO, the circuit can be small because the transmission lines to be isolated from the resonator are able to be placed near the resonator. Both a large loaded Q and a large reflection coefficient of a resonant circuit are obtained with the structure. Fabricated DR-VCO has following performances. The oscillation center frequency is 30. 242 GHz and the frequency tuning range is 91 MHz when the control voltage varies 2 to 10 V. An output power of more than 7.3 dBm and a C/N of 90 dBc/Hz at 100 kHz offset are obtained at the frequency range.

This paper describes a diakoptics approach to the field simulation of shielded structures. If the structure can be divided so that the sliced cross section is homogeneously filled with a medium in the metal-surrounded region, the frequency domain diakoptics can be effectively formulated. In the method, the partial eigenfunction expansion (or modal expansion) is utilized at the interface between the divided structures, and the finite difference time domain calculation is used to characterize some of the divided parts. The synthesis of total characteristics is demonstrated using a simple example. The issue of term truncation in the eigenfunction expansion is also addressed and an effective algorithm for the term selection (mode selection) is proposed. The techniques described here are applicable to metal package designs for efficient structure optimization.

This paper describes our new technology for creating a highly productive 0. 1 µm gate InGaP/InGaAs HEMT with a GaAs substrate for a millimeter-wave MMIC. We applied a phase-shifting photo lithographic technique and sidewall deposition/etching process to fabricate a 0. 1 µm gate electrode. The fabricated HEMTs showed excellent high-frequency performance; An MSG exceeding 10 dB at 60 GHz. We also fabricated a 60 GHz band, four-stage low-noise amplifier MMIC and demonstrated its superior performance (Gain= 27 dB and NF= 3. 1 dB @61 GHz). These results strongly suggest that our InGaP/InGaAs HEMTs technologies are highly applicable for millimeter-wave applications.

In this paper the characteristics of millimeter-wave antenna composed of layered magnetic and dielectric slabs with different corrugation are described for the transverse electric mode. A corrugation of the upper magnetic layer contacts with air, and the lower surface of the dielectric slab having corrugation in matalized. The extinction coefficient clarifying the characteristics of the leakage wave is systematically derived by using the perturbation method combined with the multiple space scales. As an example the radiation efficiency becomes a value of about 89% by using the typical physical parameters in the frequency range from 52 to 54 GHz.

A TE010 mode dielectric resonator is proposed to be used in a millimeter-wave filter. The resonator was fabricated using the photolithographic technique, and high unloaded Q of 1610 was obtained at 60 GHz. A planar circuit type millimeter-wave filter, using TE010 mode dielectric resonators, was fabricated using NRD guides as input and output circuits. The measured filter characteristics agreed with calculated values well. The filter can be applicable to future millimeter-wave mobile communications systems.

We present a design chart and a manufacturing process for mm-wave absorber consisting of two spacers (poly-carbonate) and two-resistive sheets (polyethylene terephthalate deposited with Indium Tin Oxide). The conventional design chart gives us necessary information to make a desirable absorber. Based on the design chart, a multi-layered type absorber was manufactured and it is concluded that a significant absorption level (-20dB) is attained at a wide-frequency range of 46-66GHz.