Input Impedance Matching Research Articles

A high‐performance low‐noise amplifier for 71–76, 76–77, and 77–81 GHz communication systems in 90‐NM CMOS

ABSTRACTA low power and wideband three‐stage millimeter‐wave low‐noise amplifier (LNA) for 71–76 GHz high‐speed point‐to‐point wireless link, and 76–77 GHz long‐range and 77–81 GHz short‐range automotive radars using standard 90‐nm CMOS technology is reported. T‐match technique is utilized to achieve simultaneously wideband input and output impedance matching, wideband power gain (S21) and wideband noise figure (NF) at W‐band. The LNA consumes 21.1 mW, achieving S11 better than −10 dB for frequencies 62.3–82.4 GHz, S22 better than −10 dB for frequencies 62.8–84.6 GHz, S12 better than −29 dB for frequencies 72–84 GHz, and group delay variation smaller than ±6.5 ps for frequencies 70–90 GHz. Additionally, high and flat S21 of 13.1 ± 1.5 dB is achieved for frequencies 72–84 GHz, which means the corresponding 3‐dB bandwidth is 12 GHz. Furthermore, the LNA achieves minimum NF of 6.2 dB at 78 GHz and NF of 6.8 ± 0.6 dB for frequencies 75–82 GHz, one of the best NF results ever reported for a W‐band CMOS LNA. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1673–1680, 2014

Design method of a single‐ended GM boosted common‐gate CMOS low‐noise amplifier

ABSTRACTA design method for a common‐gate (CG) low‐noise amplifier (LNA) for LTE applications is presented to have a boosted transconductance (gm) value in a single‐ended configuration. To overcome the constraint of the gm value for conventional CG LNAs for input matching, a notch filter is utilized at the singled‐ended LNA output load. With this topology, the effective gm can be freely increased for a high gain and low noise figure (NF) without affecting input impedance matching. Moreover, the linearity is also enhanced because the notch filter load can reduce high‐order harmonics of the operating frequency. A single‐ended LNA implemented in a 0.18‐μm CMOS process with this technique delivers a maximum voltage gain of 20.9 dB with a minimum NF of 2.6 dB, a third‐order intermodulation intercept point of −9 dBm with power consumption of 5.8 mW at 2.6 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1409–1412, 2014

High-Performance Wideband Low-Noise Amplifier Using Enhanced $\pi$-Match Input Network

A low noise-figure (NF) and high power gain (S21) 3 ~ 10 GHz ultra-wideband low-noise amplifier (UWB LNA) with excellent phase linearity using 0.18 μm CMOS technology is reported. An enhanced π-match input network is used to achieve wideband input impedance matching as well as high and flat S21. To achieve low and flat NF, the pole frequency and pole quality factor of the second-order NF frequency response are tuned to approximate the maximally flat condition. The LNA consumes 18 mW, achieving S11 better than -10 dB for frequency lower than 12.2 GHz and group-delay (GD) variation smaller than ±14.6 ps for frequencies 3 ~ 10 GHz. Additionally, high and flat S21 of 13.7 ± 1.5 dB is achieved for frequencies 1 ~ 12.5 GHz, which means the corresponding 3-dB bandwidth is 11.5 GHz. Furthermore, the LNA achieves minimum NF of 2.2 dB at 4 GHz and NF of 2.3 ± 0.1 dB for frequencies of 3 ~ 10 GHz, one of the best NF results ever reported for a 3 ~ 10 GHz CMOS LNA.

OPTIMIZED DESIGN OF HELICAL ANTENNA WITH PARASITIC PATCH FOR L-BAND SATELLITE COMMUNICATIONS

A new small, low-proflle and light-weight helical antenna element was designed for L-band satellite communications. The novelty of the antenna is that its input impedance matching has been improved by adjusting the copper strip matching stub, while its circular polarization performance has been enhanced by changing the parasitic radiation patch loaded in the front of the antenna. The optimal antenna structure for INMARSAT application has been fabricated and measured. The proposed antenna can produce a gain of higher than 9dB, a 3-dB axial ratio bandwidth of nearly 15%, and a jS11j < i15dB impedance bandwidth of nearly 19%. A good agreement between measurements and simulations is obtained. The proposed antenna is compact in size and easy to tune. It provides a promising antenna element for antenna array applications.

Genetic Algorithms in Antennas and Smart Antennas Design Overview: Two Novel Antenna Systems for Triband GNSS Applications and a Circular Switched Parasitic Array for WiMax Applications Developments with the Use of Genetic Algorithms

Genetic algorithms belong to a stochastic class of evolutionary techniques, whose robustness and global search of the solutions space have made them extremely popular among researchers. They have been successfully applied to electromagnetic optimization, including antenna design as well as smart antennas design. In this paper, extensive reference to literature related antenna design efforts employing genetic algorithms is taking place and subsequently, three novel antenna systems are designed in order to provide realistic implementations of a genetic algorithm. Two novel antenna systems are presented to cover the new GPS/Galileo band, namely, L5 (1176 MHz), together with the L1 GPS/Galileo and L2 GPS bands (1575 and 1227 MHz). The first system is a modified PIFA and the second one is a helical antenna above a ground plane. Both systems exhibit enhanced performance characteristics, such as sufficient front gain, input impedance matching, and increased front-to-back ratio. The last antenna system is a five-element switched parasitic array with a directional beam with sufficient beamwidth to a predetermined direction and an adequate impedance bandwidth which can be used as receiver for WiMax signals.

Low‐power 77–81 GHz CMOS LNA with excellent matching for automotive radars

A low-power and wideband three-stage 77–81 GHz low-noise amplifier (LNA) using standard 90 nm CMOS technology is reported. The T-match technique is utilised to achieve simultaneously wideband input and output impedance matching, wideband power gain (S 21) and a wideband noise figure (NF). The LNA consumes 21.1 mW, achieving S 11 better than −10 dB for the frequencies 62.3–82.4 GHz, S 22 better than −10 dB for the frequencies 62.8–84.6 GHz, S 12 better than −29 dB for the frequencies 72–84 GHz and a group delay variation smaller than ±4 ps for the frequencies 77–81 GHz. In addition, high and flat S 21 of 13.1 ± 1.5 dB is achieved for the frequencies 72–84 GHz, which means the corresponding 3 dB bandwidth is 12 GHz. Furthermore, the LNA achieves a minimum NF of 6.2 dB at 78 GHz and a NF of 6.8 ± 0.6 dB for the frequencies 75–82 GHz, one of the best NF results ever reported for a CMOS LNA for 77–81 GHz automotive radar applications.

RFID 이중 UHF 대역 인식 시스템용 안테나 소형화 설계

In this paper, a size-reduction technique is presented for the RFID reader antenna working at two UHF bands. To tackle the problem of size increase in multi-band applications, two resonance paths are made to occur in one geometry with a single feed. While one resonance path is combined with the other, the entire geometry is determined to guarantee the resonance at the target frequencies through the dual-band input impedance matching. The antenna performance is predicted by the full-wave simulation, and the design method is verified by observing the good agreement between the simulated and measured results. At the two frequencies, the satisfactory return loss as well as the antenna efficiency and peak gain of the far-field pattern is obtained.

Input impedance matching optimization for adaptive low-power low-noise amplifiers

Portable and implantable devices with wireless connectivity generate a high demand for low-power RF circuits. Biasing transistors in the subthreshold region allows significant reduction of power consumption, but calls for effective design techniques to minimize performance tradeoffs. This paper addresses one of the challenges associated with subthreshold RF low-noise amplifier (LNA) design: The input impedance of the ubiquitous CMOS inductor-degenerated common-source LNA operated in the subthreshold region is analyzed. By taking the increased impact of larger parasitic capacitances in the subthreshold region into account, the proposed input impedance equations provide more precise S11 prediction than the conventional approximation. In addition, a tuning method for the LNA's input impedance is presented to guarantee matching in the presence of manufacturing process variations. This tuning is implemented with a programmable capacitance to allow for digitally-assisted calibration. A 2.4 GHz LNA was designed in 0.18 μm CMOS technology and post-layout simulations were performed with device corner models across temperature and supply voltages variations. With these variations and ±15 % source/gate inductor tolerance, the simulated S11 (<?16 dB) of the tunable LNA is at least 8.5 dB better than for the identical reference design without tuning, while minimally affecting other performance parameters.

Three-Pole 1.3–2.4-GHz Diplexer and 1.1–2.45-GHz Dual-Band Filter With Common Resonator Topology and Flexible Tuning Capabilities

In this paper, a third-order tunable diplexer and a third-order tunable dual-band bandpass filter with flexible tuning capabilities and high selectivity are proposed. Both the diplexer and dual-band filter consist of two passbands that share a common resonator for size reduction. By adding tuning elements in the middle and ends of the common resonator, the resonant frequencies of the even and odd modes can be independently tuned, thus offering flexible tuning for multi-band operations. Also, by adding extra resonators next to the common resonator, high-order tunable multi-band filters can be obtained with higher stopband suppression. The 1.3-2.4-GHz tunable diplexer shows that the two channels can be either independently tuned or simultaneously tuned as desired. The two channels cover a fractional tuning range of 34% and 18.6%, respectively, while keeping high stopband suppressions, higher isolation, and good input impedance matching. Similarly, the 1.1-2.45-GHz tunable dual-band filter shows independent and simultaneous tuning capability operating with good impedance matching and high stopband suppression.

Compact Dual Band-Notched UWB MIMO Antenna With High Isolation

A compact dual band-notched ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna with high isolation is designed on a FR4 substrate (27 × 30 × 0.8 mm3). To improve the input impedance matching and increase the isolation for the frequencies ≥ 4.0 GHz, the two antenna elements with compact size of 5.5 × 11 mm2 are connected to the two protruded ground parts, respectively. A 1/3 λ rectangular metal strip producing a 1.0 λ loop path with the corresponding antenna element is used to obtain the notched frequency from 5.15 to 5.85 GHz. For the rejected band of 3.30-3.70 GHz, a 1/4 λ open slot is etched into the radiator. Moreover, the two protruded ground parts are connected by a compact metal strip to reduce the mutual coupling for the band of 3.0-4.0 GHz. The simulated and measured results show a bandwidth with |S11| ≤ -10 dB, |S21| ≤ -20 dB and frequency ranged from 3.0 to 11.0 GHz excluding the two rejected bands, is achieved, and all the measured and calculated results show the proposed UWB MIMO antenna is a good candidate for UWB MIMO systems.

A Full Integrated LNA in 0.18μm SiGe BiCMOS Technology

A fully integrated low noise amplifier (LNA) for wireless local area network (WLAN) application is presents. The circuit is fabricated in 0.18μm SiGe BiCMOS technology. For the low noise figure, a feedback path is introduced into the traditional inductively degenerated common emitter cascade LNA, which decreases the inductance for input impedance matching, therefore reduces the thermal noise caused by loss resistor. Impedance matching and noise matching are achieved at the same time. Measured results show that the resonance point of the output resonance network shifts from 2.4GHz to 2.8GHz, due to the parasitic effects at the output. At the frequency of 2.8GHz, the LNA achieves 2.2dB noise figure, 19.4dB power gain. The core circuit consumes only 13mW from a 1.8V supply and occupies less than 0.5mm2.

Dual‐Frequency and Dual‐Mode Circular Patch Antennas Based on Epsilon‐Negative Transmission Line

ABSTRACTDual‐frequency and dual‐mode circular patch antennas based on epsilon‐negative (ENG) transmission line have been investigated. By input impedance matching, the TM01 mode with omnidirectional radiation pattern and TM11 mode with directional radiation pattern can be excited at two separate frequencies, and then the dual‐frequency and dual‐mode operation is achieved. Compared with the conventional dual‐frequency or dual‐mode patch antennas, the new designed antenna only need one patch and one feed. More important, the omnidirectional mode of proposed antenna can be excited at lower frequency than directional mode, and the frequency ratio of the two modes can be tuned by changing the number of the ENG unit cell. The performances of the proposed antennas are studied numerically and experimentally. The measured results are in good agreement with the simulated ones. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2393–2398, 2013

Design of low power CMOS ultra wide band low noise amplifier using noise canceling technique

This paper presents a design of a low power CMOS ultra-wideband (UWB) low noise amplifier (LNA) using a noise canceling technique with the TSMC 0.18μm RF CMOS process. The proposed UWB LNA employs a current-reused structure to decrease the total power consumption instead of using a cascade stage. This structure spends the same DC current for operating two transistors simultaneously. The stagger-tuning technique, which was reported to achieve gain flatness in the required frequency, was adopted to have low and high resonance frequency points over the entire bandwidth from 3.1 to 10.6GHz. The resonance points were set in 3GHz and 10GHz to provide enough gain flatness and return loss. In addition, the noise canceling technique was used to cancel the dominant noise source, which is generated by the first transistor. The simulation results show a flat gain (S21>10dB) with a good input impedance matching less than –10dB and a minimum noise figure of 2.9dB over the entire band. The proposed UWB LNA consumed 15.2mW from a 1.8V power supply.

A Low Noise Amplifier with 1.1dB Noise Figure and +17dBm OIP3 for GPS RF Receivers

A 1.575GHz SiGe HBT(heterojunction bipolar transistor) low-noise-amplifier(LNA) optimized for Global Positioning System(GPS) L1-band applications was presented. The designed LNA employed a common-emitter topology with inductive emitter degeneration to simultaneously achieve low noise figure and input impedance matching. A resistor-bias-feed circuit with a feedback resistor was designed for the LNA input transistor to improve the gain compression and linearity performance. The LNA was fabricated in a commercial 0.18µm SiGe BiCMOS process. The LNA achieves a noise figure of 1.1dB, a power gain of 19dB, a input 1dB compression point(P1dB) of -13dBm and a output third-order intercept point(OIP3) of +17dBm at a current consumption of 3.6mA from a 2.8V supply.

An Ultra-low-power Integrated RF Receiver for Multi-standard Wireless Applications

In this paper, an ultra-low-power integrated RF front end for multi-standard is proposed. It contains a current-reuse low-noise amplifier (LNA) and a single-balanced mixer. The double resonances network helps to achieve a good input impedance matching in the required band and suppress out-of-band noise. The stacked common source (CS) LNA is adopting current-reuse of the two amplifier stages and re-using bleeding current of the mixer, which save working current considerably. By employing forward body bias technique, the proposed circuit can operate at a reduced supply voltage. In addition, the local oscillator (LO) signal forward body bias technique improves the transistors’ switching characteristic, which optimizes noise figure (NF) and linearity performances simultaneously. Fabricated in the chartered 0.18-μm RF CMOS technology, the S11 of the front-end is below −14 dB in 935~960 MHz, below −11 dB in 1805~2483 MHz. It achieves a conversion gain of 18.6~20.8 dB, the double sideband (DSB) NF of 2.3~5.1 dB. The IIP3 are −8.2 dBm at 935 MHz and −9.8 dBm at 2100 MHz. It consumes 2.1 mA from a 1 V supply voltage and occupies an active area of only 0.61 × 0.53 mm2.

Electromagnetic band‐gap based corrugated structures for reducing mutual coupling of compact 60 GHz cavity‐backed antenna arrays in low temperature co‐fired ceramics

Reducing the mutual coupling of antenna elements in 60 GHz phased arrays is an important issue because it directly affects the input impedance matching and radiation performances. This study presents an electromagnetic band-gap (EBG) based design using corrugated structures to reduce the mutual coupling between two closely placed antenna elements. An isolation enhancement of 3.6 to 10.3 dB was achieved from the proposed EBG-based corrugated structure over the unlicensed band of 57 to 66 GHz. Based on the available thickness of low temperature co-fired ceramics (LTCC) layered process, the authors built a prototype with a corrugation height of 0.7 mm and measured the port isolation and radiation performances. The experimental results show that using the corrugated design may reduce the mutual coupling by 2.1 to 4.4 dB compared with that without corrugation. In addition, the corrugated design under the thickness restriction of the LTCC process is discussed in this study. An alternative structure with an extended corrugation height is included, where the port isolation is improved by more than 3 dB over the entire band of 57 to 66 GHz.

An Active Inductor Based Low Noise Amplifier for RF Receiver

Low Noise Amplifier (LNA) is a significant part in Radio Frequency (RF) receivers and plays a key role in the chip size and the implementation cost. An LNA for RF receivers utilizing the active inductor is presented. The proposed design is an alternative solution to overcome the usage of passive inductors to reduce the chip area. Besides, the active inductor reduces the parasitic capacitors affect at high frequencies. Designed in 0.18-μm CMOS process, the LNA achieves a voltage gain of 20dB, a minimum Noise Figure (NF) of 3.1 dB with low power consumption and good input and output impedance matching at 2.45 GHz. With 0.003 mm2 chip area, the proposed design is suitable for portable wireless communication devices. DOI: http://dx.doi.org/10.5755/j01.eee.19.5.2158

Compact 50–62 GHz current‐reused low‐noise amplifier with gate‐drain transformer feedback

A compact two-stage 50–62 GHz low-noise amplifier is proposed. Gate-drain transformer feedback and the current-reuse technique are employed to achieve input impedance matching, a low noise figure and low power dissipation simultaneously. The proposed low-noise amplifier, implemented in the Global Foundries 65 nm CMOS process, exhibits a peak gain of 11.8 dB at 58.5 GHz and a minimum noise figure of 5.6 dB. It consumes 15.4 mW from 1.5 V supply with a small area of 0.12 mm2 including all testing pads.

CMOS Ultra-Wideband Low Noise Amplifier Design

This paper presents the design of ultra-wideband low noise amplifier (UWB LNA). The proposed UWB LNA whose bandwidth extends from 2.5 GHz to 16 GHz is designed using a symmetric 3D RF integrated inductor. This UWB LNA has a gain of 11 ± 1.0 dB and a NF less than 3.3 dB. Good input and output impedance matching and good isolation are achieved over the operating frequency band. The proposed UWB LNA is driven from a 1.8 V supply. The UWB LNA is designed and simulated in standard TSMC 0.18 µm CMOS technology process.

ENVELOP Antenna: A Class of Very Low Profile UWB Directive Antennas for Radar and Communication Diversity Applications

In this paper we present the concept of new electrically narrow very low profile (ENVELOP) directive antennas for low frequency radars and diversity communication applications. The basic structure consists of a short TEM horn combined with an inductive loop antenna. The proposed antenna height is 0.063 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\lambda_{{{0}}}$</tex></formula> where <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\lambda_{{{0}}}$</tex></formula> is the minimum operating wavelength and has good matching and radiation characteristics over more than an octave. It is based on the principle of crossed electric and magnetic dipoles with a TEM horn as the electric dipole and a sheet loop as the magnetic dipole. However, unlike the standard structures, the proposed structure is designed to enhance the radiation in a direction perpendicular to the TEM horn axis. This limits the maximum pattern bandwidth to about one octave but allows the antenna height along the direction of maximum radiation to be very small which is very important for airborne radars and in low frequency military communications that require conformal antennas. Three different variations of the basic structure are also presented which offer improved pattern characteristics and/or pattern and polarization diversity. Two antennas were fabricated and measured. The measured results agreed well with the simulation results and both showed that the antenna can operate over 1–2 GHz with consistent radiation pattern, low dispersion and input impedance matching performance.