Showing papers presented at "European Microwave Integrated Circuit Conference in 2014"

20 nm Metamorphic HEMT technology for terahertz monolithic integrated circuits

Abstract: A metamorphic high electron mobility transistor (mHEMT) technology with 20 nm gate length for manufacturing of terahertz monolithic integrated circuits (TMICs) is presented. The passive elements include up to four interconnection metallization layers separated by low-k dielectrics (BCB), SiN and air which can be used to realize front side signal lines. Shielding the substrate from the electromagnetic field on the wafer front side eliminates the need of a costly back side process including wafer thinning, through substrate via etching and back side metallization. The semiconductor heterostructure of the mHEMT comprises a strained pure InAs channel with high electron mobility and high electron density for proper device scaling. The realized mHEMTs achieve a source resistance rS of 0.12 Ωmm which is required to minimize resistive losses in combination with an extrinsic maximum transconductance gm_max of 2850 mS/mm. Elaborated on wafer calibration procedures and optimized test transistor layouts were used to improve the precision of the S-parameter measurements up to a frequency of 450 GHz which than could be used for model extraction. The presented 20 nm mHEMT technology was employed for the design of a compact eight stage low-noise amplifier (LNA) using miniaturized microstrip lines on BCB. The measured small signal gain of the LNA exceeds 15 dB from 500-635 GHz.

GH25-10: New qualified power GaN HEMT process from technology to product overview

Abstract: The performances and the results of the qualification plan of the new high power GaN HEMT process GH25-10 are summarized in this paper. This technology would be the first ¼ gate length process qualified in Europe on 4” SiC substrate and will be fully open in foundry mode mid of 2014. It addresses applications up to 20 GHz with state of the art figure of merits in term of power density, gain, efficiency and reliability. The first part is dedicated to the description of the process and the associated spread data analysis. A second part is focused on the review of the performances, the electrical domain of validity (operating ratings) and modeling capabilities. This view is completed by some results of the qualification process. Finally, the last part will be focused on the product development based on the GH25-10 GaN technology.

A 20-Watt Ka-band GaN high power amplifier MMIC

Abstract: A Ka-band high power amplifier MMIC developed from 0.18μm gate-length AlGaN/GaN HEMT on SiC is presented. The MMIC chip was measured on-wafer across 29GHz to 31GHz under pulsed bias condition. At VDD=28V, the MMIC achieved an output power of 19W to 21W. To the authors’ best knowledge, this is the highest output power ever reported for GaN high power amplifier MMIC at Ka-band. The 2-stage amplifier GaN MMIC has 10dB linear gain and a die-size of 4.0mm x 5.5mm. The MMIC can realize high power Solid-State Power Amplifier (SSPA) for Ka-band. Keywords—Gallium Nitride, MMIC, power amplifiers, millimeter wave

90–140 GHz frequency octupler in Si/SiGe BiCMOS using a novel bootstrapped doubler topology

Abstract: This paper presents a novel bootstrapped frequency doubler, which is used to implement a wideband frequency multiplier-by 8 with balanced differential output. In terms of conversion gain, common mode rejection, and output balance, the proposed frequency doubler achieved better performance than the conventional Gilbert-cell frequency doubler by adopting the proposed bootstrapping technique. Wideband matching was also applied to broaden the bandwidth. The circuit is implemented in 0.13μm SiGe:C BiCMOS and operated from 90-140 GHz with an 8 dB gain variation, a 22dB conversion gain, a -1 to 7 dBm output power, and a power consumption of 250mW.

A 233-GHz low noise amplifier with 22.5dB gain in 0.13μm SiGe

Abstract: A low noise amplifier (LNA) design for 230GHz applications in an advanced SiGe heterojunction bipolar transistor technology is presented. The circuit consists of a four-stage pseudo-differential cascode topology. It was implemented in a commercially available SiGe BiCMOS technology with fT/fmax of 300/450GHz. By employing positive feedback for unilateralization the small-signal gain is increased, enabling circuit operation in high frequency bands and improved efficiency. The amplifier has measured 22.5dB gain at 233GHz with a 3dB bandwidth of 10GHz and a simulated noise figure of 12.5dB. The low noise amplifier draws only 17mA from a 4V supply.

Inkjet printed flexible transmission lines for high frequency applications up to 67 GHz

Abstract: This letter introduces radio frequency(RF) characterization of ink-jet printed coplanar waveguides (CPW) with and without strain. Kapton is selected as flexible substrate with different sintering temperature. With optimized inkjet printing parameters, well defined patterns with high resolution yield low attenuation constant even when operated up to 67GHz. Finally, we demonstrate that the RF performance of CPW is barely affected by bending.

ESA perspective on the industrialisation of European GaN technology for space application

Abstract: This paper reports on the component reliability improvement activities undertaken as part of the European Space Agency (ESA) GREAT2 project, culminating in the first in-orbit demonstration of an X-band telemetry transmitter using European sourced GaN technology.

Analysis and modeling of skin and proximity effects for millimeter-wave inductors design in nanoscale Si CMOS

Abstract: Analytical models of skin effect and proximity effect were developed in this paper to calculate and predict the frequency dependent resistance, Re(Z_in) and Q for mm-wave inductor design. The derived models incorporate layout and material parameters, and frequency in an explicit form suitable for circuit simulation. The accuracy has been proven by a close match with Re(Z_in) and Q measured from mm-wave inductor (L_dc~150pH, Q_max ~17, f_SR>>65GHz) fabricated by 65nm CMOS process with 0.9μm standard top metal.

Gate waveform effects on high-efficiency PA design: An experimental validation

Abstract: In this paper, an experimental validation about the benefit of the input harmonic manipulation on the performance of a microwave power amplifier is presented. With the support of low-frequency measurements on a 0.5×1000 μm2 GaN HEMT, the importance of synthesizing the correct input waveform at the intrinsic section of the device is highlighted. A class-AB tuned-load amplifier has been considered as a case study.

A 220 to 320 GHz broadband active frequency multiplier-by-eight MMIC

Abstract: For broadband signal generation in the high millimeter-wave range we present a frequency multiplier-by-eight MMIC. The measured output tuning bandwidth from 220 to 320 GHz almost covers the entire WR-03 waveguide band (220-325 GHz). On chip interstage and post amplification result in a maximum output power of 2.5 dBm at an output frequency of 260 GHz. Due to the high multiplication factor in-band harmonics are measured with a frequency-selective method and verify the dominant presence of the wanted eighth harmonic. The MMIC is realized in a metamorphic high electron mobility transistor (mHEMT) technology with a gate length of 35nm.

Ferrite LTCC edge-guided circulator

Abstract: This paper describes a ferrite low temperature co-fired ceramic (LTCC) edge-guided circulator. Traditional Y-junction stripline circulator has one ferrite disk surrounded by a dielectric material. A design of circulator presented here uses only ferrite LTCC. The material exposed under the magnetic bias shows its ferrite properties and the rest shows the dielectric properties. It has been demonstrated that a passive ferrite component like circulator could be realized on ferrite LTCC substrate without adding other materials. So this circulator could be integrated with other RF components such as antennas, amplifiers and filters etc in System-on-Package (SoP).

Structural field plate length optimization for high power applications

Abstract: In this work, we report GaN high-electron-mobility-transistors (HEMTs) on SiC with field plates of various dimensions for optimum performance. 0.6 μm gate length, 3 μm drain source space AlGaN/GaN HEMTs with field-plate lengths of 0.2, 0.3, 0.5 and 0.7 μm have been fabricated. Great enhancement in radio frequency (RF) output power density was achieved with acceptable compromise in small signal gain. When biased at 35 V, at 3 dB gain compression, a continuous wave output power density of 5.2 W/mm, power-added efficiency (PAE) of 33% and small gain of 11.4 dB were obtained at 8 GHz using device with 0.5 μm field plate length and 800 μm gate width without using via hole technology.

An 8-way power-combining E-band amplifier in a SiGe HBT technology

Abstract: An E-band power amplifier is demonstrated in an evaluation version of a fT/fmax 300-GHz/450-GHz SiGe:C BiCMOS technology. Eight-way power combining of the outputs of transformer-matched differential-cascode unit cells is used in the final stage of the amplifier. A breakout of the final stage yields a measured small-signal gain of 14 dB at 80 GHz with a 16-GHz bandwidth, whereas a version of the amplifier with an integrated 4-way power-combined pre-driver provides 28 dB gain. In the 71-76-GHz sub-band, a saturated output power of 22 dBm with an output 1-dB compression point of 20 dBm is measured, while 19 dBm output power and a 17-dBm compression point is obtained in the 81-86-GHz band. The current consumption at a 3.3-V supply voltage is 330 mA for the output stage and 500 mA for the amplifier with an integrated pre-driver.

0.5–9 GHz CMOS variable gain amplifier with control linearization, low phase variations and self-matching

Abstract: This article presents the design of a variable gain amplifier (VGA) with a new control circuitry, enabling a linear control of the gain while ensuring input return loss matching. While changing the gain by 47dB, the phase is less than 4°, making this VGA a suitable building block for multi-antenna frontends. The VGA together with the novel control circuitry was implemented in a 180nm CMOS process. The circuit has an active area of 220μm × 110μm and consumes 6.5mA from a 1.8V power supply.

A 1.16 pJ/bit 80 Gb/s 2 11 −1 PRBS generator in SiGe bipolar technology

Abstract: A 211-1, 80Gb/s pseudo-random bit sequence (PRBS) generator, employing parallel architecture is presented. The generator is optimized to provide a high bit rate as well as a long sequence length without any need of inductive peaking for a lower power consumption, compared to PRBS generators reported in literature. The PRBS generator consists of two parallel complementary rows of linear feedback shift registers (LFSR), operating up to 40Gb/s, where the generated PRBS from each are multiplexed to provide a bit-rate of double the clock frequency, reaching up to 80Gb/s. The clock distribution network was carefully optimized for a reduced amplitude and phase error to push the boundaries of the maximum achievable bit-rate. The PRBS generator is capable of generating bit-rates ranging from 10Gb/s up to 80Gb/s, with a power consumption of 576 mW to 1 W. The circuit is manufactured in an 0.35 μm SiGe-Bipolar technology with an ft of 200 GHz.

W-band IQ sub-harmonic mixers with low LO power for cryogenic operation in large arrays

Abstract: This paper presents the design and characterization of W-band IQ sub-harmonic MMIC mixers based on the UMS BES Schottky diode process. The mixers were characterized at 300 K and 20 K physical temperature. They are a key component for the compact heterodyne multi-chip modules to be used in the 16-element Argus focal plane array, which will be deployed at the Green Bank Telescope in late 2014. The RF signal is split in quadrature using a Lange coupler, LO is split in-phase using a Wilkinson divider, and an antiparallel diode pair is used for the design of two sub-harmonically pumped mixer cells. The resulting IF outputs from the two cells are I and Q, which can be combined using an off-chip 90 degree hybrid to obtain LSB and USB. Three mixer designs are fabricated using this topology. A conversion loss between 12 to 18 dB is obtained over 80 to 120 GHz of RF for a fixed IF frequency, and over 10 GHz of IF for a fixed LO frequency. These mixers are designed to operate with low LO power without a significant loss in performance.

On the correlation between kink effect and effective mobility in InAlN/GaN HEMTs

Abstract: This paper reports on the kink effect observed in InAlN/GaN high electron mobility transistors. Electrical characterizations were carried out to point out the influence of this phenomenon on transistor behaviour. It is demonstrated that the kink effect is directly correlated to shallow traps located under the conduction band. A model is proposed to highlight the influence of scattering effects on the effective mobility, permitting to describe accurately the locus of the so-called kink voltage for a gate bias close to the pinch-off voltage. Keywords—InAlN/GaN; high electron mmobility transistor (HEMT); kink effect; effective mobility; traps

6–12 GHz double-balanced image-reject mixer MMIC in 0.25μm AlGaN/GaN technology

Abstract: The front-end circuitry of transceiver modules is slowly being updated from GaAs-based MMICs to GalliumNitride. Especially GaN power amplifiers and TR switches, but also low-noise amplifiers, offer significant performance improvement over GaAs components. Therefore it is interesting to also explore the possible advantages of a GaN mixer to complete a fully GaN-based front-end. In this paper the design-experiment and measurement results of a double-balanced image-reject mixer MMIC in 0.25 μm AlGaN/GaN technology are presented. This design features an integrated LO amplifier and active IF balun. The measured conversion loss is less than 8 dB from 6 to 12 GHz, at 0 dBm LO power.

A SiGe-based E-band power amplifier with 17.7 dBm output power and 325-GHz GBW

Abstract: A high-gain, wideband power amplifier (PA) in 0.18-μm SiGe HBT technology covering the three high-speed E-band communication channels (71-76 GHz, 81-86GHz and 92-95 GHz) is presented. The architecture is based on a class-A three stage cascode amplifier. Bandwidth enhancement is achieved using inter-stage lossy-matching and gain-staggering techniques. The PA demonstrates a peak small-signal gain of 23dB and a saturated output power (Psat) of 17.7 dBm with a 14.8% power-added efficiency (PAE). With a 3-dB gain and Psat bandwidth of about 23GHz, it shows a fractional bandwidth of more than 27%. The PA draws 115mA from a 3.3-V supply.

50 Watt S-band power amplifier in 0.25 μm GaN technology

Abstract: A 50 W S-band High Power Amplifier in the UMS GH25-10 technology is presented. In order to increase the output power per area the size of the transistors is increased beyond the maximum size modelled by the foundry. For this reason the design procedure included the measurements of a transistor and the creation of a scalable Angelov-GaN model with the use of EM simulations. An output matching design approach is adopted which intrinsically optimizes the transistor harmonic load impedance. The results show that the amplifier delivers an output power of over 50 W within the frequency range from 3.05 to 3.5 GHz at a PAE of more than 62 %. The maximum measured output power is 63 W with a PAE of 65 %.

Design of a 2 Gb/s transceiver at 60 GHz with integrated antenna in bulk CMOS technology

Abstract: This work presents the design of a 60 GHz OOK transceiver, with on-chip integrated antenna, for multi Gbit short-range wireless communication. A 65 nm bulk CMOS technology has been selected as target to prove that high-speed fully-integrated RF transceivers can be realized also with low cost digital technologies, suited for wireless consumer applications. The OOK modulation scheme allows for low complex transceiver architecture with all passive and active devices integrated on-chip. At TX side the power stage combines two class-A power amplifiers in a pseudo differential scheme, each made up of a 2 stage Common Source topology with a GT gain of 6.8 dB and a OP1dB of 8.2 dBm. The whole transmitter allows for an output power of about 11 dBm. The antenna is integrated on-chip adopting an half-wavelength dipole topology. Simulated results are a radiation efficiency of 38% and a gain of -1.76 dBi. At RX side a single-stage cascode LNA with a GT gain of 11.46 dB and a noise figure (NF) of 4.69 dB is followed by an OOK demodulator realized with a simple envelope detector. Since both antenna and LNA are integrated on-chip, the impedance matching is not constrained to a 50 Ω value, but its value can be tuned to find an optimal trade-off between NF and gain of the receiver. Combining the proposed RF transceiver with the use of Reed-Solomon channel coding in the digital baseband a data link with an effective data rate of 2 Gb/s can be implemented; the BER is less than 10-5 and 10-12 at 2 m and 1.1 m distance respectively.1

4W X-band high efficiency MMIC PA with output harmonic injection

Abstract: This paper demonstrates a MMIC GaN X-band PA designed to have improved efficiency by second harmonic power injection at the output that helps shape the time-domain waveforms across the drain. The MMIC contains a class-AB PA with a nominal 4-W (36 dBm) output power at 10GHz and a small-signal gain of 14dB. The best results with harmonic injection were measured at 10.6 GHz with 3.5W (35.44 dBm) of output, showing an increase in drain efficiency from 48.5% without injection to 70% when 26.2 dBm was injected at 21.2 GHz. In order to maximize the total efficiency, which includes the efficiency of the injection circuit, a second harmonic efficient amplifier is integrated in the same GaN MMIC. The 20-GHz PA needs to provide a power on the order of Pout - 10dB, and is measured to output 27dBm with 8dB gain and PAE=59%. The relationship between the total efficiency and injector efficiency is derived and shows that the total efficiency is not appreciably affected by the injector efficiency if a second-harmonic amplifier with a gain greater than 6-7dB and with a PAE > 40% is employed.

A 100W decade bandwidth, high-efficiency GaN amplifier

Abstract: This paper will report a 100W, 100MHz to 1GHz GaN amplifier module having a minimum efficiency of 48% across the whole band with a minimum gain of 14dB. This is believed to be the highest power/efficiency combination yet reported for this frequency range.

Compact Unequal Wilkinson Power Divider With Large Power Dividing Ratio

Abstract: A compact unequal Wilkinson power divider with arbitrary power division is analyzed and demonstrated in this paper The power divider can be designed with arbitrary power division in theory and achieves large power dividing ratio in practice The proposed structure is compatible with single layer integration by using the normal PCB fabrication process The complete analytical procedures of the proposed power divider are presented To verify our proposed design approach in theory, one 11:1 unequal power divider is designed and fabricated The measured bandwidth at 20 dB return losses is about 6%, while the isolation of the two output ports is better than 20 dB Good agreement between the measured and simulated amplitude distributions is observed The phase difference between outputs ports are about ±25 degree, over the 10% relative frequency bandwidth

Design of a switched injection-locked oscillator at 2.45 GHz for a local positioning system

Abstract: In this paper, a fully integrated active reflector transponder for the localization and quick evacuation of passengers in the sea in case that passengers are overboard is presented. The backscatter tag is based on a cross-coupled oscillator topology using the switched injection-locked oscillator (SILO) principle and is implemented in a frequency modulated continuous wave (FMCW) radar. Furthermore, a novel theory for calculating the input referred noise power of a SILO is applied. The presented backscatter tag operates at 2.45 GHz and reaches a steady-state output power of 7.5 dBm. The measured input referred noise power of the SILO reaches a remarkable value of -80 dBm.

A 17.5-dBm D-band power amplifier and doubler chain in SiGe BiCMOS technology

Abstract: A D-Band ×2 frequency multiplier-amplifier chain implemented in a fT/fMAX = 200/250GHz 0.12μm SiGe BiCMOS technology is presented. The chain achieves a peak output power of 17.5dBm at 115GHz and consists of input balun and push-push frequency doubler which drives a balanced three stages Power Amplifier (PA). It operates from 108GHz to 128GHz (3 dB power bandwidth) with 3dBm input power at V-Band and consumes a total DC power of 600mW. The PA achieves output 1dB compression point and saturated power of 13.3 and 17.1dBm, respectively, at 120GHz and peak small signal gain of 25.5dB.

X-band outphasing power amplifier with internal load modulation measurements

Abstract: This paper presents a general measurement based design method for outphasing amplifiers. Both isolated and non-isolated combiners are designed based on individual PA load-pull measurements, in order to load modulate two 0.15μm GaN MMIC power amplifiers at 10.1GHz. Load modulation measurements are performed at ports internal to the PA, with the inclusion of couplers in the combiner and a four-port LSNA, to gain insight into the dynamics of load modulation during outphasing operation. Both outphasing systems exhibit a peak PAE greater than 41.5% at a peak output power greater than 35.7 dBm.

High linearity active GaN-HEMT down-converter MMIC for E-band radar applications

Abstract: A down-converter MMIC in 100 nm gate length AlGaN/GaN HEMT technology achieves an input-related 1-dB compression point of 13 dBm at a center frequency of 77 GHz, providing high linearity for radar applications. The single-ended fundamental mixer without preor post-amplification shows 8 dB conversion loss when driven with 13 dBm of LO power within an RF frequency range exceeding 75 to 81 GHz. The high linearity is achieved by operating the GaN transistor as active transconductance mixer, allowing for a high voltage swing of the RF signal even when using a relatively small transistor size as required by the high operating frequency.

A 8–40 GHz, 8 mW LNA with 27 dB peak gain and 5.2 dB NF for multiband applications

Abstract: An extremely-wideband, 8-40 GHz, low power Low Noise Amplifier (LNA) is presented in this paper. The LNA utilizes a novel combination of design techniques, namely resistive feedback, emitter degeneration, and shunt-peaked split-inductor to provide wideband input and noise matching. Furthermore, the LNA is designed as 3-stage amplifier to provide better gain control through stagger-tuning method, to meet gain specification across the entire band. The proposed LNA was implemented in 0.18 μm SiGe BiCMOS process with 150 GHz fT. The design achieves a peak gain of 27 dB with minimum Noise Figure (NF) of 5.2 dB. The gain of the LNA is greater than 15.2 dB and NF is less than 7.2 dB from 8-40 GHz. The LNA consumes only 6.7 mA from a 1.2 V supply and occupies an area of only 0.26 mm2. Using the proposed architecture, this work demonstrates LNA with extremely wide bandwidth and 3.7X improvement in FoM over comparable state-of-the-art designs.

A 240 GHz Multiplier Chain with -0.5 dBm Output Power in SiGe BiCMOS Technology

Abstract: A 240GHz ×4 frequency multiplier chain implemented in a fT/fMAX = 200/250GHz commercially available 0.12μm SiGe BiCMOS technology is presented. The chain achieves a peak output power of -0.5dBm (0.9mW) and consists of two balanced doublers driven by a differential two stages cascode power amplifier. It operates from 232GHz to 246GHz (3 dB power bandwidth) with 5dBm input power at 60GHz and consumes a total DC power of 520mW. The D-Band PA achieves output 1dB compression point and saturated power of 11.2 and 15.3dBm, respectively at 120GHz and 15.5dB small signal gain.