A $W$ -Band Photonic Transmitter/Mixer Based on High-Power Near-Ballistic Uni-Traveling-Carrier Photodiode (NBUTC-PD)

In this letter, we demonstrate a $W$-band photonic transmitter/mixer fabricated by the flip-chip bonding of a high-power back-illuminated near-ballistic uni-traveling-carrier photodiode (NBUTC-PD) and an end-fire quasi-Yagi antenna on an AlN substrate. This end-fire and directional antenna design eliminates the need for the integration of an additional Si-lens into the antenna for directional power transmission. The high bias dependent nonlinearity of the integrated NBUTC-PD means that the bias modulation technique can be used to directly up-convert the intermediate-frequency signal to a millimeter-wave signal at $W$ -band without using a costly high-speed optical modulator. A reasonable detected power ($-$ 17 dBm at 106 GHz) can be achieved with the demonstrated device with a high-output photocurrent (30 mA) and a low internal-conversion loss ($-$2.4 dB) between the radio-frequency and local-oscillator signals at $W$-band.      

Q-Band pHEMT and mHEMT Subharmonic Gilbert Upconversion Mixers

This letter makes a comparison between Q-band 0.15 $mu{rm m}$ pseudomorphic high electron mobility transistor (pHEMT) and metamorphic high electron mobility transistor (mHEMT) stacked-LO subharmonic upconversion mixers in terms of gain, isolation and linearity. In general, a 0.15 $mu{rm m}$ mHEMT device has a higher transconductance and cutoff frequency than a 0.15 $mu{rm m}$ pHEMT does. Thus, the conversion gain of the mHEMT is higher than that of the pHEMT in the active Gilbert mixer design. The Q-band stacked-LO subharmonic upconversion mixers using the pHEMT and mHEMT technologies have conversion gain of $-$7.1 dB and $-$0.2 dB, respectively. The pHEMT upconversion mixer has an ${rm OIP}_{3}$ of $-$12 dBm and an ${rm OP}_{1 {rm dB}}$ of $-$24 dBm, while the mHEMT one shows a 4 dB improvement on linearity for the difference between the ${rm OIP}_{3}$ and ${rm OP}_{1 {rm dB}}$. Both the chip sizes are the same at 1.3 mm $times$ 0.9 mm.      

17 GHz RF Front-Ends for Low-Power Wireless Sensor Networks

A 17 GHz low-power radio transceiver front-end implemented in a 0.25 $mu{hbox {m}}$ SiGe:C BiCMOS technology is described. Operating at data rates up to 10 Mbit/s with a reduced transceiver turn-on time of 2 $mu{hbox {s}}$, gives an overall energy consumption of 1.75 nJ/bit for the receiver and 1.6 nJ/bit for the transmitter. The measured conversion gain of the receiver chain is 25–30 dB into a 50 $Omega$ load at 10 MHz IF, and noise figure is 12 $pm$0.5 dB across the band from 10 to 200 MHz. The 1-dB compression point at the receiver input is $-$37 dBm and ${hbox{IIP}}_{3}$ is $-$25 dBm. The maximum saturated output power from the on-chip transmit amplifier is $-$1.4 dBm. Power consumption is 17.5 mW in receiver mode, and 16 mW in transmit mode, both operating from a 2.5 V supply. In standby, the transceiver supply current is less than 1 $mu{hbox {A}}$.      

Integration and Characteristics of 40-Gb/s Electroabsorption Modulator Integrated Laser Module With a Driver Amplifier and Bias Tees

Integration of a 40-Gb/s electroabsorption modulator integrated distributed feedback (DFB) laser (EML) module with a driver amplifier and bias tee was investigated. For the EML fabrication the selective area growth (SAG) technique was adopted for the first time. It is shown that, with the SAG technique, the 3-dB bandwidth of about 45 GHz was measured in the electrical to optical response, and the return loss (S11) of below $-$10 dB was achieved for up to 50 GHz . To integrate a bias tee within the module, a right-angle bent coplanar waveguide (CPW) was developed. The right-angle bent CPW was characterized with S11 of below $-$ 10 dB for up to 35 GHz and insertion loss (S21) of about $-$1.4 dB for up to 40 GHz . The whole integrated module including the EML, a driver amplifier, and bias tee was characterized under the conditions of an operating temperature of 25 $^{circ}{rm C}$, the modulator bias of 1.4 V, and the DFB laser current of 40 mA. S11 of below $-$10 dB was obtained for up to 14 GHz and the measured electrical-to-optical response has 3-dB bandwidth of about 20 GHz.      

A 47 GHz Cross-Coupled VCO Employing High- Island-Gate Varactor for Phase Noise Reduction

A 47 GHz $LC$ cross-coupled voltage controlled oscillator (VCO) employing the high-$Q$ island-gate varactor (IGV) based on a 0.13 $mu{rm m}$ RFCMOS technology is reported in this work. To verify the improvement in the phase noise, two otherwise identical VCOs, each with an IGV and a conventional multi-finger varactor, were fabricated and the phase noise performance was compared. With $V_{DD}$ of 1.2 V and core power consumption of 3.86 mW, the VCOs with the IGV and the multi-finger varactor have a phase noise of $-$95.4 dBc/Hz and $-$91.4 dBc/Hz respectively, at 1 MHz offset, verifying the phase noise reduction with the introduction of the high-$Q$ IGV. The VCO with IGV exhibited an output power of around $-$15 dBm, leading to a FoM of $-$182.9 dBc/Hz and a tuning range of 3.35% (45.69 to 47.22 GHz).      

125-GHz Diode Frequency Doubler in 0.13-$mu{hbox {m}}$ CMOS

The first mm-wave Schottky diode frequency doubler fabricated in CMOS is demonstrated. The doubler built in 130-nm CMOS uses a balanced topology with two shunt Schottky barrier diodes, and exhibits $sim$10-dB conversion loss as well as $-$1.5-dBm output power at 125 GHz. The input matching is better than $-$10$~$dB from 61 to 66 GHz. The rejection of fundamental signal at output is greater than 12 dB for input frequency from 61 to 66$~$GHz. The doubler can generate signals up to 140 GHz.      

10-GHz and 20-GHz Channel Spacing High-Resolution AWGs on InP

This letter reports on 10-GHz and 20-GHz channel-spacing arrayed waveguide gratings (AWGs) based on InP technology. The dimensions of the AWGs are 6.8$,times,$8.2 mm$^{2}$ and 5.0$,times,$6.0 mm$^{2}$, respectively, and the devices show crosstalk levels of $-$12 dB for the 10-GHz and $-$17 dB for the 20-GHz AWG without any compensation for the phase errors in the arrayed waveguides. The root-mean-square phase errors for the center arrayed waveguides were characterized by using an optical vector network analyzer, and are 18 $^{circ}$ for the 10-GHz AWG and 28$^{circ}$ for the 10-GHz AWG.      

A 0.1–5 GHz Cryogenic SiGe MMIC LNA

In this letter, the design and measurement of the first SiGe integrated-circuit LNA specifically designed for operation at cryogenic temperatures is presented. At room temperature, the circuit provides greater than 25.8 dB of gain with an average noise temperature $(T_{e})$ of 76 K $(NF=1 {rm dB})$ and $S_{11}$ of $-$ 9 dB for frequencies in the 0.1–5 GHz band. At 15 K, the amplifier has greater than 29.6 dB of gain with an average $T_{e}$ of 4.3 K and $S_{11}$ of $-$14.6 dB for frequencies in the 0.1–5 GHz range. To the authors' knowledge, this is the lowest noise ever reported for a silicon integrated circuit operating in the low microwave range and the first matched wideband cryogenic integrated circuit LNA that covers frequencies as low as 0.1 GHz.      

Polymeric Substrate Spin-Cast diF-TESADT OTFT Circuits

We report 7- and 15-stage spin-cast contact-crystallized 2, 8-difluoro-5, 11-bis(triethylsilylethynyl) anthradithiophene (diF-TESADT) organic thin-film transistor (OTFT) ring oscillators on plastic substrates with a maximum frequency of more than 22 kHz and a propagation delay of less than 3.3 $ muhbox{s/stage}$ at a supply bias of $-$80 V. The circuits have stable operation for a supply bias as small as $-$ 3 V (25–30 $muhbox{s/stage}$). Spin-cast diF-TESADT OTFTs from a toluene solution on plastic substrates have a mobility of 0.1–0.2 $hbox{cm}^{2}/hbox{V} cdot hbox{s}$ with a contact-related microstructure from pentafluorobenzenethiol-treated Au source and drain electrodes.      

A $Q$ -Band Four-Element Phased-Array Front-End Receiver With Integrated Wilkinson Power Combiners in 0.18-$mu{{hbox{m}}}$ SiGe BiCMOS Technology

A four-element phased-array front-end receiver based on 4-bit RF phase shifters is demonstrated in a standard 0.18- $mu{{hbox{m}}}$ SiGe BiCMOS technology for $Q$-band (30–50 GHz) satellite communications and radar applications. The phased-array receiver uses a corporate-feed approach with on-chip Wilkinson power combiners, and shows a power gain of 10.4 dB with an ${rm IIP}_{3}$ of $-$13.8 dBm per element at 38.5 GHz and a 3-dB gain bandwidth of 32.8–44 GHz. The rms gain and phase errors are $leq$1.2 dB and $leq {hbox{8.7}}^{circ}$ for all 4-bit phase states at 30–50 GHz. The beamformer also results in $leq$ 0.4 dB of rms gain mismatch and $leq {hbox{2}}^{circ}$ of rms phase mismatch between the four channels. The channel-to-channel isolation is better than $-$35 dB at 30–50 GHz. The chip consumes 118 mA from a 5-V supply voltage and overall chip size is ${hbox{1.4}}times {hbox{1.7}} {{hbox{mm}}}^{2}$ including all pads and CMOS control electronics.      

Novel NiGe MSM Photodetector Featuring Asymmetrical Schottky Barriers Using Sulfur Co-Implantation and Segregation

We report the first demonstration of a novel germanium (Ge) metal–semiconductor–metal (MSM) photodetector featuring asymmetrical Schottky-barrier height for low dark current and high-speed photodetection applications. Through co-implantation and segregation of valence-mending adsorbate such as sulfur at the NiGe/Ge interface, the germanide Fermi level can be pinned close to the conduction band edge. This results in an effective modulation of hole Schottky-barrier height, leading to a significant dark current suppression by $≫$3 orders of magnitude over a conventional MSM photodetector. When operated at a bias voltage $V_{A}$ of 1.0 V, a detector with an area of 804 $muhbox{m}^{2}$ shows a spectrum response of $sim$0.36 A/W or a corresponding quantum efficiency of $sim$34%. In addition, a frequency response measurement reveals the achievement of a $-$3-dB bandwidth of $sim!$15 GHz at an illumination photon wavelength of 1550 nm.      

14-GHz GaNAsSb Unitraveling-Carrier 1.3-$muhbox{m}$ Photodetectors Grown by RF Plasma-Assisted Nitrogen Molecular Beam Epitaxy

We report on picosecond pulsed response and 3-dB cutoff frequency of 1.3-$ muhbox{m}$ GaNAsSb unitraveling-carrier photodetectors (PDs) grown by molecular beam epitaxy using a radio-frequency plasma-assisted nitrogen source. The 0.1-$muhbox{m}$ -thick GaNAsSb photoabsorption layer contains 3.5% of N and 9% of Sb, resulting in a bandgap of 0.88 eV. The dark current densities at 0 and $-$9 V are 6 and 34 $hbox{mA}/hbox{cm}^{2}$, respectively. The GaNAsSb UTC PDs exhibit a temporal response width of 46 ps and a record 3-dB cutoff frequency of 14 GHz at $-$9 V.      

Integrated Quadrature Couplers and Their Application in Image-Reject Receivers

Several fully-integrated multi-stage lumped-element quadrature hybrids that enhance bandwidth, amplitude and phase accuracies, and robustness are presented, and a fully-integrated double-quadrature heterodyne receiver front-end that uses two-stage Lange/Lange couplers is described. The Lange/Lange cascade exploits the inherent wide bandwidth characteristic of the Lange hybrid and enables a robust design using a relatively low transformer coupling coefficient. The measured image-rejection ratio is $>$ 55 dB over a 200 MHz bandwidth centered around 5.25 $~$GHz without any tuning, trimming, or calibration; the front-end features 23.5 dB gain, $-$79 dBm sensitivity, 5.6 dB SSB NF, $-$7$~$ dBm IIP3, $-$18 dB $S_{11}$ and a 1 mm $times$ 2 mm die area in 0.18$ mu{hbox {m}}$ CMOS.      

Ultrathin Si Thin-Film Transistor on Glass

We have studied the fabrication of ultrathin single-crystalline-silicon thin-film transistors (TFTs) on glass. The single-crystalline Si layer was transferred to glass by hydrogen implantation and anodic bonding. The thickness of the silicon-on-glass (SiOG) was controlled down to 10 nm by dry etching. The p-channel SiOG TFTs with 10-nm-thick Si exhibited the field-effect mobility of 134.9 $hbox{cm}^{2}/hbox{V}cdot hbox{s}$, threshold voltage of $-$1.5 V, and gate voltage swing of 0.13 V/dec. The TFTs were found to be stable against gate bias stress of $+$30 or $-$30 V.      

A Single-Ended Fully Integrated SiGe 77/79 GHz Receiver for Automotive Radar

A single-ended 77/79 GHz monolithic microwave integrated circuit (MMIC) receiver has been developed in SiGe HBT technology for frequency-modulated continuous-wave (FMCW) automotive radars. The single-ended receiver chip consists of the first reported SiGe 77/79 GHz single-ended cascode low noise amplifier (LNA), the improved single-ended RF double-balanced down-conversion 77/79 GHz micromixer, and the modified differential Colpitts 77/79 GHz voltage controlled oscillator (VCO). The LNA presents 20/21.7 dB gain and mixer has 13.4/7 dB gain at 77/79 GHz, and the VCO oscillates from 79 to 82 GHz before it is tuned by cutting the transmission line ladder, and it centres around 77 GHz with a tuning range of 3.8 GHz for the whole ambient temperature variation range from $- hbox{40},^{circ}{hbox{C}}$ to $+ hbox{125},^{circ}{hbox{C}}$ after we cut the lines by tungsten-carbide needles. Phase noise is $-$90 dBc/Hz@1 MHz offset. Differential output power delivered by the VCO is 5 dBm, which is an optimum level to drive the mixer. The receiver occupies 0.5 ${hbox{mm}}^{2}$ without pads and 1.26 ${hbox{mm}}^{2}$ with pads, and consumes 595 mW. The measurement of the whole receiver at 79 GHz shows 20–26 dB gain in the linear region with stable IF output signal. The input ${rm P}_{rm 1dB}$ of the receiver is $-$35 dBm.      

Monolithic Integration of a Multiplexer/Demultiplexer With a Thermo-Optic VOA Array on an SOI Platform

In this letter, a nine-channel 100-GHz arrayed waveguide grating multiplexer/demultiplexer is monolithically integrated with a Mach–Zehnder interferometer thermo-optic variable optical attenuators (VOAs) arrayed on a silicon-on-insulator platform. The on-chip transmission loss is $sim$6 dB and the crosstalk is less than $-$25 dB for the transverse-electric mode. The maximum modulation depths of different thermo-optic VOAs are similar, $sim$ 15 dB with 2.7-V bias. The frequency response of our device is fast ($geq$ 100 kHz) for thermo-optic effect devices. The maximum power consumption of a single VOA is less than 35 mW.      

$L$ -Band Polarization-Independent Reflective SOA for WDM-PON Applications

An $L$-band polarization-independent reflective semiconductor optical amplifier (RSOA) is demonstrated for the first time. Optical gain of greater than 21 dB and gain flatness better than 4 dB is achieved over the $L$-band. The polarization-dependent gain estimated using a polarization resolved spectrum is less than 1 dB over the $L$-band. The measured output saturation power is $-$1.0 dBm and the noise figure (NF) is 10 dB for the packaged device. The 3-dB frequency bandwidth for the device is 1.3 GHz making it suitable for 1.25-Gb/s modulated wavelength-division-multiplexed passive optical network networks. Further, the saturation power and the NF of the RSOA were compared with an SOA of identical length.      

CMOS Avalanche Photodiode Embedded in a Phase-Shift Laser Rangefinder

This paper presents the design and the characterization of a CMOS avalanche photodiode (APD) working as an optoelectronic mixer. The $hbox{P}^{+}hbox{N}$ photodiode has been implemented in a commercial 0.35-$muhbox{m}$ CMOS technology after optimization with SILVACO. The surface of the active region is $ hbox{3.78} cdot hbox{10}^{-3} hbox{cm}^{2}$. An efficient guard-ring structure has been created using the lateral diffusion of two n-well regions separated by a gap of 1.2 $mu hbox{m}$. When biased at $-$2 V, the best responsitivity $S_{lambda ,{rm APD}} = hbox{0.11} hbox{A/W}$ is obtained at $lambda = hbox{500} hbox{nm}$. This value can easily be improved by using an antireflection coating. At $lambda = hbox{472} hbox{nm}$, the internal gain is about 75 at $-$6 V and 157 at $-$7 V. When biased at $-$6 V, the APD achieves a dark current of 128 $muhbox{A} cdot hbox{mm}^{-2}$ and an excess noise factor $F = hbox{20}$ . Then, the APD is successfully used as an optoelectronic mixer to improve the signal-to-noise ratio of a low-voltage embedded phase-shift laser rangefinder.      

A 22–29-GHz UWB Pulse-Radar Receiver Front-End in 0.18-$mu{hbox{m}}$ CMOS

The design of a CMOS 22–29-GHz pulse-radar receiver (RX) front-end for ultra-wideband automotive radar sensors is presented. The chip includes a low-noise amplifier, in-phase/quadrature mixers, a quadrature voltage-controlled oscillator (QVCO), pulse formers, and baseband variable-gain amplifiers. Fabricated in a 0.18-$mu{hbox{m}}$ CMOS process, the RX front-end chip occupies a die area of 3 ${hbox{mm}}^{2}$. On-wafer measurements show a conversion gain of 35–38.1 dB, a noise figure of 5.5–7.4 dB, and an input return loss less than $-$14.5 dB in the 22–29-GHz automotive radar band. The phase noise of the constituent QVCO is $-$107 dBc/Hz at 1-MHz offset from a center frequency of 26.5 GHz. The total dc power dissipation of the RX including output buffers is 131 mW.      

VCSEL Module With Polymer Optical Output Rods to Enable High Efficiency Coupling for Optical Interconnection

New vertical-cavity surface-emitting laser (VCSEL) modules—designed with a optical output rod surrounded by cladding—have been proposed to realize high-efficiency low-cost optical interconnection. Prototypes have been fabricated using a photomask transfer method employing two kinds of ultraviolet curable resin. Observation of the near-field pattern and eye pattern for signal transmission shows that output rods with a diameter of 50- $mu$m efficiently confine the laser beam as an optical waveguide. In addition, ray tracing simulation indicates that this new VCSEL offers greater positional tolerance—as much as $+$18/ $-$22 $mu$m—for coupling to optical wiring in 90$^{circ}$ light path conversion.