Active Integrated Antenna Research Articles

Compensated circuit with characteristics of lossless double negative materials and its application to array antennas

A compensated circuit showing the characteristics of lossless double negative (DNG) materials is proposed and applied to an active integrated antenna array. A properly selected matching circuit produces the phase advance, which is characteristic of a left-handed wave (backward-wave), and the lossy resonant circuit generates the negative group velocity. An amplifier is used to compensate for the inherent loss of the resonant circuit, including its resistor. Then, a series-fed antenna array with a proposed DNG circuit is also designed and fabricated. It consists of two subarrays, each made of two aperture-coupled patch antennas, and the DNG circuit block inserted between the subarrays. In comparison to a conventional array, without the DNG circuit whose two subarrays are connected directly by a microstrip line, the proposed array shows a negligible beam squint and flat gain, over a considerable bandwidth of 11%.

Circularly polarized broadband high‐efficiency active integrated antenna

AbstractThis letter presents a circularly polarized (CP) broadband high‐efficiency active integrated antenna, where the broadband CP antenna is integrated directly with a broadband high‐efficiency class‐E power amplifier (PA). To achieve CP operation, a series feed using an L‐shaped microstrip feed line below the ground plane is used to provide a 90° phase shift between crossed slots. The antenna serves both functions of a broadband CP radiator and a broadband harmonics‐termination load network for the class‐E PA. Measures results demonstrate both broadband CP radiation and high efficiency. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2145–2148, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21940

W-Band Active Integrated Antenna Oscillator Based on Full-Wave Design Methodology and 0.1- m Gate InP-Based HEMTs

An active integrated antenna (AIA) oscillator consisting of an active circuit and planar antenna on the same substrate can be used as a high-performance, low-cost, small component for millimeter-to-sub-millimeter wave applications. We describe a highly extended, finite-difference-time-domain full-wave analysis method for designing AIA circuits precisely. It treats active devices as distributed elements. Using this method and 0.1-μm-gate InP-based HEMTs, we fabricated W-band AIA oscillators with an oscillation frequency of 111 GHz.

Broadband high-efficiency circularly polarized active antenna and array for RF front-end application

This paper presents a broadband high-efficiency circularly polarized (CP) active integrated antenna, and a broadband CP active array at 2 GHz. To realize the broadband CP antenna, a circular patch is aperture coupled by crossed slots in the ground plane, which are fed by an L-shaped microstrip feed line below the ground. The antenna is designed to serve the functions of both a radiator and a harmonics-terminated load for class-E high-efficiency power-amplifier (PA) integration. The broadband CP active antenna is realized by directly integrating the broadband CP antenna with the class-E PA. It achieves a 9% bandwidth (1.84-2.01 GHz) for axial ratio (AR) below 3 dB, and a 12% bandwidth for power-added efficiency (PAE) over 60%. To form the broadband CP active array, four active antenna elements are sequentially rotated, and each element is directly integrated with broadband class-E PA. A low-cost printed-circuit-board technology is employed in fabrication and a pseudomorphic high electron-mobility transistor is used. A peak drain efficiency of 71.5% for the class-E amplifier is measured at 1.95 GHz. The active array achieves a peak-effective radiated power of 39.7 dBm, and PAE is over 50% within a 22.6% bandwidth (1.72-2.16 GHz). The AR is below 3 dB over a 27% bandwidth (1.72-2.26 GHz).

Broadband high-efficiency linearly and circularly polarized active integrated antennas

This paper presents the design, fabrication, and measurements of two broadband high-efficiency active integrated antennas (AIAs) operating in linear polarization and circular polarization, respectively. A new design method is proposed for designing the broadband load network of the class-E power amplifier (PA), so that a high power-added efficiency (PAE) can be achieved over a broad bandwidth. A broadband high-efficiency class-E PA is designed based on the proposed method. The linearly polarized (LP) AIA is realized by integrating the broadband class-E PA with a broadband LP antenna, which uses a ring-slot coupled microstrip patch antenna. Then, the circularly polarized (CP) AIA is realized by integrating the broadband class-E PA with a broadband CP antenna, which uses a single-feed cross-slot-coupled microstrip patch antenna. Each antenna is designed for working as both a radiator and a harmonics-terminated load. A low-cost printed-circuit-board technology is employed in fabrication, and a p-high-electron mobility transistor is used. The PAE of the LP AIA is over 50% within a 14.6% bandwidth from 1.78 to 2.06 GHz, while the PAE of the CP AIA is over 50% within a 14% bandwidth from 1.92 to 2.21 GHz. The axial ratio of the CP AIA is below 3 dB over a 9% bandwidth from 1.99 to 2.18 GHz.

Design of Active Integrated Antenna for Dual Frequency Image Rejection

This paper is discusses a new configuration of integrated antenna for dual frequency operations and image frequency rejection. Microstrip patch antenna is design in such away to operate in dual frequencies band. The RF 90° hybrid, LNA's, mixers, LO and IF coupler are integrated to a dual frequency microstrip patch antenna to produce a single module of integrated antenna system that can perform for in dual-band frequencies. The design technique and simulation result for active integrated antenna (AIA) with image rejection is presented.

An H-shaped harmonic suppression active integrated antenna

An active integrated antenna (AIA), which integrates an H-shaped microstrip antenna and a bipolar junction transistor (BJT) oscillator on a substrate, is proposed to suppress its harmonic radiation. The measurement results show good harmonic suppression. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006.

High-efficiency class-B push–pull amplifying array for microwave transmitting front end

The authors present a novel push–pull amplifying array using quadruple antenna-patch couplers and dual-feed antennas. It exploits the advantages of both class-B push–pull amplifiers and active integrated antennas (AIAs), resulting in a high-efficiency, linear and yet compact design. A state-of-the-art heterojunction FET power amplifier of 50% peak power-added efficiency (PAE) is achieved at 10 GHz. A three-element array prototype was successfully built, achieving a peak antenna gain of 19.6 dBi. This is 5.7 and 10.4 dB better than amplifying arrays using the antenna-patch coupler approach and the conventional parallel feeding network, respectively.

DESIGN OF AN ACTIVE INTEGRATED ANTENNA FOR A PCMCIA CARD

This paper presents the design and implementation of an Active Integrated Antenna (AIA) using a Voltage Controlled Oscillator (VCO) for applications in the Industrial Scientific Medical band (2.4 ÷ 2.4835 GHz). Surface Mounting Device (SMD) technology has been applied in the realization of the passive and active components, and low cost FR-4 dielectric slabs have been employed for the integration of the antenna and the active/transmissive circuits, residing, respectively, on the opposite faces of a Personal Computer Memory Card International Association (PCMCIA) card. The proposed layout makes use of a properly corrugated ground plane, i.e., a High Impedance Ground Plane (HIGP), to improve the antenna performances and to minimize the coupling between the radiating component and other possible radiating elements and/or electronic circuits residing nearby. The analysis and the design of the radiating element with the HIGP are based on a rigorous full wave Method of Moment (MoM) formulation developed in the Spectral Domain (SD), while the design of the active circuitry is developed through the commercial tool AWR Microwave Office. The final design of the component is obtained hybridizing the 254 Bilotti, Urbani, and Vegni two methods and applying a Genetic Algorithm (GA) optimization tool in order to take advantage of the HIGP, while keeping the geometrical dimensions of the antenna suitable for mounting on a PCMCIA card, and maintaining the antenna performances acceptable. The measured results show the performances of the VCO, an antenna gain of 19.4 dBi and an increased front-to-back radiation ratio compared to the one of the same antenna mounted on a standard Perfect Electric Ground Plane (PEGP). This result, thus, demonstrates the minimization of the interferences between the designed antenna and other possible radiating and transmissive devices residing nearby.

Active integrated antenna using T‐shaped microstip‐line‐fed slot antenna

AbstractAn active integrated antenna (AIA), which consists of a T‐shaped microstrip‐line‐fed slot antenna, is proposed. Since the designed antenna has an electromagnetically coupled feedback loop, it can easily solve the problem of DC isolation between ports of the amplifier. The fabricated parallel feedback antenna oscillator shows stable oscillation at a frequency of 10.05 GHz. The measured EIRP is 37.79 mW, and the cross‐polarization levels are at least −15‐dB lower than those of co‐polarization for all directions. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 367–370, 2006; Published online in Wiley InterScience (www. interscience.wiley.com). DOI 10.1002/mop.21351

A 2.4‐GHz wireless‐over‐fiber transceiver using photonic active integrated antennas (PhAIAs)

AbstractThe integration of a vertical cavity surface emitting laser (VCSEL) and a photodiode with two microstrip antennas results in low‐cost wireless‐optical transmitter and receiver modules and the initial microwave‐link results are shown. The VCSEL antenna is used as part of a fully bidirectional wireless‐optical link and data are successfully transferred between two wireless‐enabled laptops. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 233–237, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21315

VCO active integrated antenna with reactive impedance surfaces

AbstractIn this paper, we present the design of an active integrated antenna (AIA) using a voltage‐controlled oscillator (VCO) for applications in the Industrial Scientific Medical (ISM) band (2.4 to 2.4835 GHz). The realized active circuit makes use of compact devices in surface‐mounting device (SMD) technology, while the passive radiating element is placed over a reactive‐impedance surface (RIS), properly designed to show an inductive surface impedance within the operative frequency band. The final layout has been optimized in terms of dimensions to achieve the integration of the antenna and the active/transmissive circuits on the opposite faces of a Personal Computer Memory Card International Association (PCMCIA) card. The design is conducted through the employment of a rigorous method of moments (MoM) formulation, used for the design of the antenna, and of a commercial tool for the nonlinear analysis of the active circuitry. Some preliminary experimental results are also presented to illustrate the features of the antenna here proposed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 82–86, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21088

Active Integrated Antenna Techniques for Beam Control

Active integrated antenna techniques have high potential for giving smaller size, lighter weight, lower cost and higher efficiency, in particular to millimeter-wave circuit-antenna systems. This paper gives a review of active integrated antenna techniques with emphasis on beam steering and retrodirective antenna arrays. Various beam steering operations of integrated antenna oscillator arrays using locking phenomena are presented. Beam steering arrays of such type have the feature that phase shifters are not necessary in the arrays. Arrays with higher harmonic output radiation can enlarge the beam steering range. Arrays of locked active antennas which operate as self-oscillating mixers can be beam controllable receiving antennas.

An improved design of microstrip patch antennas using photonic bandgap structure

Microstrip antennas inherently have a high input impedance at resonant frequency. This may not be convenient for some applications. For active integrated antennas, moreover, the radiated power of microstrip antennas needs to be very low at harmonic frequencies. The main goals of this study are impedance matching and harmonic suppression of microstrip antennas. In order to meet these requirements, two one-dimensional (1-D) photonic bandgap (PBG) structures, namely, the defected ground structure (DGS) and the compact microstrip resonant cell (CMRC), are applied to the feed line of microstrip antennas. The characteristic impedance of the microstrip line is controlled by the additional effective inductance of the PBG structure. Without any matching circuits, microstrip antennas can be easily fed by a simple 50 /spl Omega/ microstrip line with a PBG structure at the operating frequency. Additionally, the second harmonic of the proposed antennas is properly suppressed compared to a conventional antenna. Measured results indicate that the two PBG structures are quite effective for harmonic suppression. Therefore, the proposed antennas are suitable for active integrated antennas.

Active integrated antenna using T-shaped microstrip-line-fed slot antenna

An active integrated antenna (AIA) which consists of a T-shaped microstrip-line-fed slot antenna is proposed. Since the designed antenna has an electromagnetically coupled feedback loop, it can easily solve the problem of DC isolation between a radiator and amplifier. The fabricated parallel-feedback antenna oscillator shows stable oscillation at a frequency of 10.05 GHz. The measured effective isotropic radiated power (EIRP) is 37.79 mW, and the cross-polarization levels are at least −15-dB lower than those of co-polarization for all directions. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 538–540, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21041

A varactor-tuned active-integrated antenna using slot antenna

A varactor-tuned active antenna which consists of a series feedback voltage-controlled oscillator (VCO) and a well matched slot antenna is proposed. The fabricated antenna shows stable oscillation at 5.8 GHz band, and the frequency varied from 5.73 to 5.97 GHz, with less than 1.28 dB of amplitude deviation over the frequency range. Since the fabricated active antenna is a simple structure where the operating frequency can be easily tuned through the varactor diode, it may be used as an element in phase-shifterless beam scanning systems. In addition, a capacitor for dc blocking is not necessary due to isolation between the active and radiating element.

Effect of a Cavity Enclosure on the Resonant Frequency of Inverted Microstrip Circular Patch Antenna

The inverted microstrip circular patch (IMCP) antenna has been analyzed very recently by the present authors and the same microstrip structure enclosed in a cylindrical cavity has been employed by others to develop various active integrated antennas. In this paper, the effect of the cylindrical enclosure in changing the resonant frequency of an IMCP has been studied both theoretically and experimentally. The cavity-effect critically depends on the enclosed patch and the cavity dimensions which are thoroughly investigated to help a designer in choosing the antenna parameters. An efficient analytical formulation is also proposed to predict accurate resonant frequencies of the cavity enclosed IMCPs and is verified with different experimental data.

FDTD analysis of active integrated antenna with amplifier

AbstractIn this paper, an FDTD analysis is carried out for an active integrated antenna with an amplifier. The GaAs FET used in the amplifier is expressed in terms of TriQuint's Own Model (TOM) and the numerical results of its state equation are combined with the FDTD method by way of the voltage source method. As a result of investigation of the method for application of the bias voltage in a 8.5‐GHz low‐noise amplifier, it is found that convergence to the set voltage is obtained by applying the voltages via shorting pins after all bias circuits are modeled. Also, the analysis and experimental results of the radiation patterns of the active patch antenna are compared. It is found that the cross polarization level is increased due to the currents flowing in the drain bias line placed near the patch antenna. Finally, the radiation characteristics of the active slot antenna are investigated. It is confirmed that the cross polarization can be reduced by separating the radiating part and the circuit part on opposite sides of the substrate. The method proposed in this paper allows design of the entire antenna structure integrated with active devices, including the effect of the coupling between the circuit elements, impedance matching conditions, and radiation patterns. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(11): 21–29, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10213

Analysis for active integrated antenna arrays with 2D- and 3D-printed EBGs

A nonlinear circuit simulator and an electromagnetic simulator based on FDTD analysis are combined simultaneously to obtain circuit characteristics and field distribution for analysis of a 10-GHz slot antenna with a printed electromagnetic band gap (EBG) structure and a 23-GHz active integrated antenna (AIA) array. Experimentally, the printed EBG exhibits good performance in the active integrated antenna. The injection-reflection matching method in the time domain via a data file, called the via-file data-matching technique, is proposed as a simulation technique to connect with different types of simulation as well as different analytical conditions. The results are compared with those obtained using commercial software packages. The characteristics obtained from the simulation agreed with the experimental data, and the field distribution created by the simulator can help us understand wave-propagation behavior in the array. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14: 262–273, 2004.

A dual-gate FET subharmonic injection-locked self-oscillating active integrated antenna for RF transmission

A planar subharmonic injection-locked GaAs dual-gate MESFET (DGMESFET) self-oscillating active integrated antenna (AIA) is presented for RF transmission. The oscillation is obtained with one gate of the DGMESFET at 2.052 GHz, and the stabilization of the oscillation is achieved by injecting a small subharmonic low-noise signal into the other gate of the DGMESFET. Phase noise was measured to be -98 dBc/Hz at the 10 KHz offset. The structure was shown to have the potential in performing triple functions of radiation, low noise oscillation and mixing (or modulation), a capability required for low cost wireless systems such as RFID tags and indoor positioning systems.