Enrichment of Package Antenna Approach With Dual Feeds, Guard Ring, and Fences of Vias

This paper enriches the package antenna approach to wireless modules by introducing the dual feeds, the guard ring, and fences of vias. The dual feeds enable the antenna for not only single-ended but also differential signal operations. The guard ring and fences of vias reduce the antenna backward radiation and improve the isolation between the antenna and radio chip. The design guideline of the guard ring and fence of vias for the package antenna approach is developed for the first time. An example antenna of this package approach using a microstrip patch radiator has been designed and fabricated in a low-temperature cofired ceramic (LTCC) technology for the wireless modules operating at the 5-GHz band. The antenna has a size of 17 $,times,$17 $,times,$2 mm $^{3}$ and contains the open cavity that is large enough to accommodate a radio chip of current size. Simulated and measured input impedance matching and far-field radiation properties are discussed. They show that the antenna achieves over 2.2% bandwidth while maintaining 90% efficiency.      

Design of a Beam Switching/Steering Butler Matrix for Phased Array System

A compact broadband 8-way Butler matrix integrated with tunable phase shifters is proposed to provide full beam switching/steering capability. The newly designed multilayer stripline Butler matrix exhibits an average insertion loss of 1.1 dB with amplitude variation less than $pm$2.2 dB and an average phase imbalance of less than 20.7$^{circ}$ from 1.6 GHz to 2.8 GHz. The circuit size is only $160times 100 {rm mm}^{2}$, which corresponds to an 85% size reduction compared with a comparable conventional microstrip 8-way Butler matrix. The stripline tunable phase shifter is designed based on the asymmetric reflection-type configuration, where a Chebyshev matching network is utilized to convert the port impedance from 50 $Omega$ to 25 $Omega$ so that a phase tuning range in excess of 120$^{circ}$ can be obtained from 1.6 GHz to 2.8 GHz. To demonstrate the beam switching/steering functionality, the proposed tunable Butler matrix is applied to a 1 $times$ 8 antenna array system. The measured radiation patterns show that the beam can be fully steered within a spatial range of 108 $^{circ}$.      

Antenna-in-Package and Transmit–Receive Switch for Single-Chip Radio Transceivers of Differential Architecture

A fully differential architecture from the antenna to the integrated circuit is proposed for radio transceivers in this paper. The physical implementation of the architecture into truly single-chip radio transceivers is described for the first time. Two key building blocks, the differential antenna and the differential transmit–receive (T–R) switch, were designed, fabricated, and tested. The differential antenna implemented in a package in low-temperature cofired-ceramic technology achieved impedance bandwidth of 2%, radiation efficiency of 84%, and gain of 3.2 dBi at 5.425 GHz in a size of 15$times$15$times$1.6 ${hbox {mm}}^{3}$. The differential T–R switch in a standard complementary metal–oxide–semiconductor technology achieved 1.8-dB insertion loss, 15-dB isolation, and 15-dBm 1-dB power compression point ($P_{1,{hbox {dB}}}$) without using additional techniques to enhance the linearity at 5.425 GHz in a die area of 60$times$40 $mu{hbox {m}}^{2}$.      

Broadband Microstrip Antenna With Left-Handed Metamaterials

A novel type of microstrip antenna is proposed for compact wideband wireless applications. The antenna is composed of six unit cells of left-handed metamaterial (LHM) and a dipole element. The dipole is directly connected to three of six LHM unit cells, which are arranged in a 2 $times$ 3 antenna array form. In this aspect, the proposed antenna is regarded as LHM loaded dipole antenna. The antenna is matched with a stepped impedance transformer and rectangular slot in the truncated ground plane. The coupled LH resonances and simultaneous excitation of different sections of unit cells and dipole result into broad bandwidth. The proposed antenna has a maximum gain of $-$1 dBi at 2.5 GHz. The measured return loss indicates 63% bandwidth for $vert{rm S}11vert≪-10 {rm dB}$ over the band of 1.3–2.5 GHz. The overall size of LHM loaded antenna is $lambda_{0}/2.87timeslambda_{0}/11.27timeslambda_{0}/315.80$ at the center frequency. The radiation of the electrically small LHM unit cells is also demonstrated by the simulated radiation pattern, which is an important concept for the antenna miniaturization.      

A 0.13 $mu$ m CMOS Quad-Band GSM/GPRS/EDGE RF Transceiver Using a Low-Noise Fractional-N Frequency Synthesizer and Direct-Conversion Architecture

This paper presents a single-chip CMOS quad-band (850/900/1800/1900 MHz) RF transceiver for GSM/GPRS/EDGE applications which adopts a direct-conversion receiver, a direct-conversion transmitter and a fractional-N frequency synthesizer with a built-in DCXO. In the GSM mode, the transmitter delivers 4 dBm of output power with 1$^{circ}$ RMS phase error and the measured phase noise is ${-}$164.5 dBc/Hz at 20 MHz offset from a 914.8$~$MHz carrier. In the EDGE mode, the TX RMS EVM is 2.4% with a 0.5 $~$dB gain step for the overall 36 dB dynamic range. The RX NF and IIP3 are 2.7 dB/ ${-}$12 dBm for the low bands (850/900 MHz) and 3 dB/${-}$ 11 dBm for the high bands (1800/1900 MHz). This transceiver is implemented in 0.13 $mu$m CMOS technology and occupies 10.5 mm$^{2}$ . The device consumes 118 mA and 84 mA in TX and RX modes from 2.8 V, respectively and is housed in a 5$,times,$ 5 mm$^{2}$ 40-pin QFN package.      

A Wideband PLL-Based G/FSK Transmitter in 0.18 $mu$m CMOS

A wideband phase-locked loop (PLL)-based G/FSK transmitter (TX) architecture is presented in this paper. In the proposed TX, the G/FSK data is applied outside the loop; hence, the data rate is not constrained by the PLL bandwidth. In addition, the PLL remains locked all the time, preventing the carrier frequency from drifting. In this architecture, the G/FSK modulation signal is generated from a proposed Sigma-Delta modulated Phase Rotator $(SigmaDelta{hbox{-PR}})$. By properly combining the multi-phase signals from the PLL output, the $SigmaDelta{hbox{-PR}}$ effectively operates as a fractional frequency divider, which can synthesize modulation signals with fine-resolution frequencies. The proposed $SigmaDelta{hbox{-PR}}$ adopts the input signal as the phase transition trigger, facilitating a glitch-free operation. The impact of the $SigmaDelta{hbox{-PR}}$ on the TX output noise is also analyzed in this paper. The proposed TX with the $SigmaDelta{hbox{-PR}}$ is digitally programmable and can generate various G/FSK signals for different applications. Fabricated in a 0.18 $muhbox{m}$ CMOS technology, the proposed TX draws 6.3 mA from a 1.4 V supply, and delivers an output power of $-$11 dBm. With a maximum data rate of 6 Mb/s, the TX achieves an energy efficiency of 1.5 nJ/bit.      

Quasi Microstrip Leaky-Wave Antenna With a Two-Dimensional Beam-Scanning Capability

A quasi microstrip leaky-wave antenna (QMLWA) with a two-dimensional (2-D) beam-scanning capability is presented in this paper. QMLWA consists of two half-width microstrip leaky-wave antennas with a phase-shifter. This new type of microstrip leaky-wave antenna has the advantages of reducing size, 2-D beam-scanning and suppressing back lobes. The main lobe scanning in H-plane ($y-z$ plane) is achieved through varying the operating frequency. When the operating frequency increases from 4.4–6 GHz, the main lobe scans from 84 $^{circ}$ to 26 $^{circ}$ in H-plane continuously. The main lobe steers in quasi-E-plane with varying the phase difference between two half-width microstrip leaky-wave antennas. The lobe scans from 78$^{circ}$ to 103$^{circ}$ in quasi-E-plane at 5.4 GHz. The experimental results show this short QMLWA (about 2 wavelengths) leaks power effectively. The back lobe in H-plane of QMLWA is suppressed 13 dB as compared with the conventional whole width MLWA at 5.4 GHz as example. The H-plane radiation characteristics of QMLWA are mainly determined by the width $s$ of half-width MLWA and the distance $D$ between two half-width MLWA together. This size-reduced QMLWA is useful in the automotive radar system and air traffic control.      

Varactor-Loaded H-Shaped Antenna With Radiation Pattern Control

A varactor-loaded H-shaped antenna with radiation pattern control is described. The antenna has a varactor in each of the four arms. A cylindrical wire model with four varactors is analyzed by the method of moments. The analysis, using the “FEKO” simulator, shows the figure-of-eight radiation pattern is rotated by 360$^{circ}$ in the plane of the antenna with variation of capacitances of the four varactors. An optimum set of capacitances is derived, considering the beamwidth, null level of the radiation pattern, and voltage standing wave ratio (VSWR). A prototype antenna implemented on FR4 substrate has dimensions of 60 mm by 200 mm with a line width of 2 mm. The dc voltages were supplied to the four varactors via the antenna arms where slits were inserted. A 110 $Omega$ feed line and 110 $Omega$-to-50 $Omega$ balun were designed for the minimum VSWR, whilst maintaining good radiation properties. The antenna exhibits rotation of a figure-of-eight radiation pattern with a VSWR less than 2.7, and the maximum gain from ${-}2.9$ dBi to 1.4 dBi at 750 MHz.      

A 66 $mu$ W 86 ppm$/^{circ}$ C Fully-Integrated 6 MHz Wienbridge Oscillator With a 172 dB Phase Noise FOM

This paper presents the design of a new Wienbridge topology. Its phase noise performance, low temperature dependency and low power consumption make it suitable for use in wireless sensor nodes and time-based sensor readout circuitry. The noise as well as temperature behavior of the oscillator is explained using extensive calculations. Measurements on 7 samples of the same batch show a temperature stability of 86 $hbox{ppm}/^{circ}hbox{C}$ and a measured spread of 0.9% at an oscillation frequency of 6 MHz. The circuit consumes 66 $muhbox{W}$ and is realized in a 65 nm technology measuring 150 $muhbox{m}$ by 200 $muhbox{m}$. The measured phase noise figure of merit is 172 dB at a frequency offset of 100 kHz.      

Single- and Dual-Polarized Tunable Slot-Ring Antennas

Single- and dual-polarized slot-ring antennas with wideband tuning using varactor diodes have been demonstrated. The single-polarized antenna tunes from 0.95 to 1.8 GHz with better than ${-}13$ dB return loss. Both polarizations of the dual-polarized antenna tune from 0.93 to 1.6 GHz independently with better than ${-}10$ dB return loss and $> !20!$ dB port-to-port isolation over most of the tuning range. The capacitance of the varactor diodes varies from 0.45 to 2.5 pF, and the antennas are printed on 70 $,times,$70 $,times,$0.787 mm ${^3}$ substrates with ${epsilon_{rm r} = 2.2}$. The dual-polarized slot-ring antenna can either be made both frequency- and polarization-agile simultaneously, or can operate at two independent frequencies on two orthogonal polarizations. To our knowledge, this is the first dual-polarized tunable antenna with independent control of both polarizations over a 1.7:1 frequency range.      

A Low-Voltage Mobility-Based Frequency Reference for Crystal-Less ULP Radios

The design of a 100 kHz frequency reference based on the electron mobility in a MOS transistor is presented. The proposed low-voltage low-power circuit requires no off-chip components, making it suitable for application in wireless sensor networks (WSN). After a single-point calibration, the spread of its output frequency is less than 1.1% (3$sigma $) over the temperature range from $-{hbox{22}},^{circ}{hbox{C}}$ to 85$,^{circ}{hbox{C}}$ . Fabricated in a baseline 65$~$nm CMOS technology, the frequency reference circuit occupies 0.11$ hbox{mm}^{2}$ and draws 34 $ muhbox{A}$ from a 1.2 V supply at room temperature.      

An Analytical Method to Extract the Physical Parameters of a Solar Cell From Four Points on the Illuminated $J{-}V$ Curve

For a variety of solar cells, it is shown that the single exponential $J{-}V$ model parameters, namely—ideality factor $eta$ , parasitic series resistance $R_{s}$, parasitic shunt resistance $R_{rm sh}$, dark current $J_{0}$, and photogenerated current $J_{rm ph}$ can be extracted simultaneously from just four simple measurements of the bias points corresponding to $V_{rm oc}$, $sim!hbox{0.6}V_{rm oc}$, $J_{rm sc}$, and $sim! hbox{0.6}J_{rm sc}$ on the illuminated $J{-}V$ curve, using closed-form expressions. The extraction method avoids the measurements of the peak power point and any $dJ/dV$ (i.e., slope). The method is based on the power law $J{-}V$ model proposed recently by us.      

Novel Design of a 2.5-GHz Fully Integrated CMOS Butler Matrix for Smart-Antenna Systems

This paper presents a novel design of monolithic 2.5-GHz 4 $,times,$4 Butler matrix in 0.18- $mu$m CMOS technology. To achieve a full integration of smart antenna system monolithically, the proposed Butler matrix is designed with the phase-compensated transformer-based quadrature couplers and reflection-type phase shifters. The measurements show an accurate phase distribution of ${hbox{45}}{pm}{hbox{3}}^{circ}, ~{hbox{135}} pm {hbox{4}}^{circ}, ~ -{hbox{45}} pm {hbox{3}}^{circ}, ~{hbox{and}}~ -{hbox{135}} pm {hbox{4}}^{circ}$ with amplitude imbalance less than 1.5 dB. The antenna beamforming capability is also demonstrated by integrating the Butler matrix with a 1$,times,$ 4 monopole antenna array. The generated beams are pointing to $-{hbox{45}}^{circ}, ~ -{hbox{15}}^{circ}$ , 15$^{circ}$, and 45$^{circ}$, respectively, with less than 1$^{circ}$ error, which agree very well with the predictions. This Butler matrix consumes no dc power and only occupies the chip area of 1.36 $,times,$1.47 mm$^{2}$ . To our knowledge, this is the first demonstration of the single-chip Butler matrix in CMOS technology.      

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 $mu{hbox {A}}$.      

Novel Composite Phase-Shifting Transmission-Line and Its Application in the Design of Antenna Array

A novel composite phase-shifting transmission line (TL) with designable characteristics is presented, which can be used to achieve arbitrary phase of the transmission coefficient at any required frequency with a certain length of the TL. An empirical formula is given of the relationship between the phase and physical length of the composite TL at a required frequency. A sample of 0$^{circ}$ phase-shifting TL is designed in details, and is verified by the full-wave simulation. At the required frequency of 5 GHz, the amplitude of ${rm S}_{21}$ is equal to $-0.23~{rm dB}$ with a phase of $-0.467^{circ}$. The electric length is only $0.212lambda_{0}$ , which has been decreased by 68.5% compared to the conventional microstrip line. Using the proposed composite TL, an antenna array is designed with two radiation patches excited by the novel series feed-line. The detailed procedure of such design is presented. The lowest reflection coefficient is exactly achieved at the required frequency of 5 GHz. The maximum radiation is obtained at $theta_{0}=0^{circ}$ , which indicates that the 0$^{circ}$ phase-shifting TL works very well. The sample is also fabricated and good agreements between simulation and measurement results are obtained.      

A Sub-100 $mu{rm W}$ Ku-Band RTD VCO for Extremely Low Power Applications

This letter presents the microwave performance of a sub-100 $mu{rm W}$ Ku-band differential-mode resonant tunneling diode (RTD)-based voltage controlled oscillator (VCO) with an extremely low power consumption of 87 $mu{rm W}$ using an InP-based RTD/HBT MMIC technology. In order to achieve the extremely low-power Ku-band RTD VCO, the device size of RTD is scaled down to $0.6times 0.6 mu{rm m}^{2}$. The obtained dc power consumption of 87 $mu{rm W}$ is found to be only 1/18 of the conventional-type MMIC VCOs reported in the Ku-band. The fabricated RTD VCO has a phase noise of $-$100.3 dBc/Hz at 1 MHz offset frequency and a tuning range of 140 MHz with the figure-of-merit (FOM) of $-$194.3 dBc/Hz.      

Metallic Wire Array as Low-Effective Index of Refraction Medium for Directive Antenna Application

Two-dimensional (2-D) metallic wire arrays are studied as effective media with an index of refraction less than unity $(n_{rm eff}≪1)$. The effective medium parameters (permittivity $varepsilon_{rm eff}$, permeability $mu_{rm eff}$ and $n_{rm eff}$) of a wire array are extracted from the finite-element simulated scattering parameters and verified through a 2-D electromagnetic band gap (EBG) structure case study. A simple design methodology for directive monopole antennas is introduced by embedding a monopole within a metallic wire array with $n_{rm eff}≪1$ at the antenna operating frequencies. The narrow beam effect of the monopole antenna is demonstrated in both simulation and experiment at X-band (8–12 GHz). Measured antenna properties including reflection coefficient and radiation patterns are in good agreement with simulation results. Parametric studies of the antenna system are performed. The physical principles and interpretations of the directive monopole antenna embedded in the wire array medium are also discussed.      

Analysis and Design of a CMOS UWB LNA With Dual- -Branch Wideband Input Matching Network

A wideband low-noise amplifier (LNA) based on the current-reused cascade configuration is proposed. The wideband input-impedance matching was achieved by taking advantage of the resistive shunt–shunt feedback in conjunction with a parallel LC load to make the input network equivalent to two parallel $RLC$-branches, i.e., a second-order wideband bandpass filter. Besides, both the inductive series- and shunt-peaking techniques are used for bandwidth extension. Theoretical analysis shows that both the frequency response of input matching and noise figure (NF) can be described by second-order functions with quality factors as parameters. The CMOS ultra-wideband LNA dissipates 10.34-mW power and achieves ${ S}_{11}$ below $-$8.6 dB, ${ S}_{22}$ below $-$10 dB, ${ S}_{12}$ below $-$26 dB, flat ${ S}_{21}$ of 12.26 $pm$ 0.63 dB, and flat NF of 4.24 $ pm$ 0.5 dB over the 3.1–10.6-GHz band of interest. Besides, good phase linearity property (group-delay variation is only $pm$22 ps across the whole band) is also achieved. The analytical, simulated, and measured results agree well with one another.      

2 MHz AO $Q$ -switched ${rm TEM}_{00}$ Grazing Incidence Laser With 3 at.% Neodymium Doped Nd:YVO$_{4}$

We present a detailed experimental and theoretical study of the ultrahigh repetition rate AO $Q$ -switched ${rm TEM}_{00}$ grazing incidence laser. Up to 2.1 MHz $Q$-switching with ${rm TEM}_{00}$ output of 8.6 W and 2.2 MHz $Q$ -switching with multimode output of 10 W were achieved by using an acousto-optics $Q$ -switched grazing-incidence laser with optimum grazing-incidence angle and cavity configuration. The crystal was 3 at.% neodymium doped Nd:YVO$_{4}$ slab. The pulse duration at 2 MHz repetition rate was about 31 ns. The instabilities of pulse energy at 2 MHz repetition rate were less than ${pm}6.7hbox{%}$ with ${rm TEM}_{00}$ operation and ${pm}3.3hbox{%}$ with multimode operation respectively. The modeling of high repetition rate $Q$-switched operation is presented based on the rate equation, and with the solution of the modeling, higher pump power, smaller section area of laser mode, and larger stimulated emission cross section of the gain medium are beneficial to the $Q$-switched operation with ultrahigh repetition rate, which is in consistent with the experimental results.      

A Parallel Pruned Bit-Reversal Interleaver

A parallel algorithm and architecture for pruned bit-reversal interleaving (PBRI) are proposed. For a pruned interleaver of size $N$ with mother interleaver size $M=2^{n} geq N$, the proposed algorithm interleaves any number $xin [0,N-1]$ in at most $n-1$ steps, as opposed to $x$ steps using existing PBRI algorithms. A parallel architecture of the proposed algorithm employing simple logic gates and having a short critical path delay is presented. The proposed architecture is valuable in reducing (de-)interleaving latency in emerging wireless standards that employ PBRI channel (de-)interleaving in their PHY layer such as the 3GPP2 Ultra Mobile Broadband standard.