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Showing papers on "L band published in 2016"


Journal ArticleDOI
TL;DR: Results from flight trials conducted to investigate the characteristics of the L-band air-to-ground radio channel for positioning applications show that the setup is suitable for investigating both multipath structure and absolute propagation time of the radio signals.
Abstract: In the paper, we present results from flight trials conducted to investigate the characteristics of the L-band air-to-ground radio channel for positioning applications. We discuss the employed hardware setup, synchronization concept, calibration procedures, and investigated flight patterns. It is shown that the setup is suitable for investigating both multipath structure and absolute propagation time of the radio signals. The power delay and Doppler power profiles, as well as the time-of-arrival estimation accuracy, are presented. Manuscript

35 citations


Proceedings ArticleDOI
01 Jun 2016
TL;DR: In this article, a novel design of ultrawideband origami quasi-taper antenna that can be reconfigured to operate from 1.28 GHz to 4.12 GHz at three different states of height, and the operating bandwidths at the 3 states are respectively 1.64 GHz, 1.56 GHz, and 3.6 GHz.
Abstract: This paper presents a novel design of ultrawideband origami quasi-taper antenna that can be reconfigured to operate from 1.28 GHz to 4.12 GHz at 3 different states of height, and the operating bandwidths at the 3 states are respectively 1.28 GHz–1.64 GHz (25%), 1.64 GHz–3.56 GHz (74%) and 3.56 GHz–4.12 GHz (14.6%). Therefore, this antenna can be applied for kinds of wireless communications in L band and S band with unidirectional radiations. Simulated realized gain at the 3 states of antenna height in their operating frequency bands are respectively greater than 6 dB (H=271 mm), 8.5 dB (H=147 mm) and 5 dB (H=57 mm). Right-hand circular polarization happens at state 2 from 2.04 GHz to 3.56 GHz (fractional circular polarization bandwidth=54%), and the CP bandwidth is better than the standard monofilar and previously proposed origami conical spiral antenna, while polarizations at the other 2 states are either linear or elliptical in their operating frequency bands.

13 citations


Proceedings ArticleDOI
TL;DR: The DVA1 (Dish Verification Antenna 1) as discussed by the authors is a single-piece composite-material radio telescope developed at the National Research Council Canada (NRC), which has a feed-high offset Gregorian optical design with a primary effective diameter of 15 m.
Abstract: DVA1 (Dish Verification Antenna 1) is a highly innovative rim-supported single-piece composite-material dish radio telescope developed at the National Research Council Canada (NRC). It has a feed-high offset Gregorian optical design with a primary effective diameter of 15 m. DVA1 has been undergoing mechanical and astronomical system tests since 2014. Astronomical measurements were made in L band using a prototype front end developed for MeerKAT by EMSS Antennas (South Africa), including aperture efficiency, beam profiles, sensitivity, and tipping curves. The clean shaped optics, careful attention to feed design, and high sensitivity of the L band receiver (Trx ~ 6 K) yield a system with high aperture efficiency (~ 0.8), excellent sensitivity (~ 9 m2/K), and low spillover (~ 4 K). Observations of 21 cm atomic hydrogen lines towards standard sources demonstrate the low stray radiation pickup of the antenna. Ku band holography has measured the effective surface accuracy and stability of the dual-reflector antenna. The effective RMS of ~ 0.85 mm implies a Ruze efficiency of ~ 0.88 at 10 GHz and ~ 0.60 at 20 GHz. The surface is stable (~ 10% variation in surface RMS) over the limited range of environmental conditions tested. Testing continues for characterization of pointing, low frequency performance (< 1 GHz), and polarimetric performance. NRC is developing a successor antenna, DVA3, which will have a more accurate surface and be usable at frequencies at least up to Q band (30 – 50 GHz).

12 citations


Journal ArticleDOI
TL;DR: In this article, the dominant scattering mechanism for wheat and soybean in the L and C bands is analyzed by simulating the bistatic scattering echoes in multiple viewpoints, which can help us understand the interaction between incident wave and vegetation parameters.
Abstract: Compared with the backscattering configuration, the bistatic scattering echoes can provide multidimensional information on land surface. Based on the Michigan Microwave Canopy Scattering (MIMICS) model, a first-order microwave bistatic scattering model for vegetations is developed in this paper. The dominant scattering mechanism for wheat and soybean in the L and C bands is analyzed by simulating the bistatic scattering echoes in multiple viewpoints, which can help us understand the interaction between incident wave and vegetation parameters. The influence of crop height, leaf size and moisture of vegetations and down layer soil on the scattering echoes is fully investigated. The simulations show that the bistatic scattering echoes are more sensitive to the vegetation parameters than that in backscattering configuration. There exist optimal scattering angles, in specular direction and in direction perpendicular to the incident plane, to improve the retrieval accuracy of vegetation parameters and moisture of soil surface. Moreover, the simulations demonstrate that bistatic scattering echoes in high frequency (C band) are a good choice to retrieve the vegetation parameters, and the echoes in low frequency (L band) are preferred to retrieve the soil parameters. This research can be used to provide reference for crop monitoring and future bistatic system design.

9 citations



Proceedings ArticleDOI
TL;DR: The design and performances of the radio receiver system installed at the Sardinia Radio Telescope (SRT) are presented and the radio receivers, which under test and under construction and which are needed for expanding the telescope observing capabilities are given.
Abstract: In this article, we present the design and performances of the radio receiver system installed at the Sardinia Radio Telescope (SRT). The three radio receivers planned for the first light of the Sardinian Telescope have been installed in three of the four possible focus positions. A dual linear polarization coaxial receiver that covers two frequency bands, the P-band (305-410 MHz) and the L-band (1.3-1.8 GHz) is installed at the primary focus. A mono-feed that covers the High C-band (5.7-7.7 GHz) is installed at the beam waveguide foci. A multi-beam (seven beams) K-band receiver (18- 26.5 GHz) is installed at the Gregorian focus. Finally, we give an overview about the radio receivers, which under test and under construction and which are needed for expanding the telescope observing capabilities.

9 citations


Journal ArticleDOI
TL;DR: In this paper, a three-port MMIC-based quasi-circulator for UHF and L bands is presented, which uses differential amplifier and lossy broadband combiner to obtain effective phase cancellation for high directivity.
Abstract: This letter presents a compact, broadband three-port MMIC-based quasi circulator for UHF and L bands. As a motivation and application, the use of this circuit in a network analyzer is presented. The circuit is designed using differential amplifier and lossy broadband combiner to obtain effective phase cancellation for high directivity. The designed quasi circulator has return losses at all ports better than 10 dB and reverse isolation above 30 dB in the frequency range from 0.2 to 2.5 GHz. The quasi circulator has directivity of 15 to 52 dB and load dynamic range of 10 to 49 dB, over the 0.2 to 1.7 GHz band. The proposed circuit thus can be used in portable network analyzers and other applications designed for the UHF and L bands.

8 citations


Proceedings ArticleDOI
Ying Wu1, Chengjin Jin1, Jianping Fan1, Xiaoli Zhao1, Lei Yu1, B. Du 
01 Aug 2016
TL;DR: In this paper, the blue print of the FAST PAF development and corresponding scientific goals are introduced, as well as the progress has been made in these PAFs, and a detailed description of the progress can be found.
Abstract: Phased array feed (PAF) is an emerging technology which can greatly improve the survey speed of telescopes. As a world-class radio telescope, the Five-hundred-meter Aperture Spherical radio Telescope (FAST) is also trying to enhance its observation capability and open up new scientific studies at several frequency bands by PAFs. At the first partof this paper, the blue print of the FAST PAFs development and corresponding scientific goals are introduced, as well as the progress has been made in these PAFs.

7 citations


Proceedings ArticleDOI
01 Aug 2016
TL;DR: In this paper, a wideband low-noise amplifier using a new equalization structure was proposed, which works from 1 GHz to 2.6 GHz and the gain of the amplifier is more than 35 dB.
Abstract: This paper prevents a wideband low noise amplifier worked in L band and S band using a new equalization structure. Usually, in order to design a wideband amplifier, we should use an equalization to compensate for inconsistencies in active component's gain response. Microstrip equalizer is always composed of microstrip transmission line coupled with microstrip resonators and resistance. It is known that the limit of a traditional microstrip equalization corresponding is the one quarter length transmission line. So it usually can work only in an octave band. In the paper, we prevent a novel equalization that can work a wide band which the high frequency of the work band is more than three time the low frequency of the work band. And the equalization is also smaller than traditional equalization. We finally use design a equalization which works from 1 GHz to 3 GHz. Then we designed a wideband low noise amplifier using the equalization. This LNA works from 1 GHz to 2.6 GHz. It covers over the GPS band to WiFi band. This amplifier is cascaded by three pHEMT ATF54143. The gain of the amplifier is more than 35 dB. And it simulation noise figure is below 1.1 dB all over the band. The substrate we use is FR4 with the thickness of 0.8 mm.

7 citations


Proceedings ArticleDOI
01 Feb 2016
TL;DR: Different Wilkinson Power Divider Networks using stepped multiple sections of the conventional Wilkinson Divider are presented in this article, where the operating frequency range has been chosen as 1.25 GHz to 1.45 GHz.
Abstract: Different Wilkinson Power Divider Networks using stepped multiple sections of the conventional Wilkinson Divider are presented in this paper. The operating frequency range has been chosen as 1.25 GHz to 1.45 GHz. As, the chosen frequency range lies in the L band, these power dividers can be used as feeding network for antenna arrays operated in the L band. We have fabricated and tested the 2∶1, 4∶1, 8∶1 and 16∶1 Wilkinson Power Divider Networks to validate all their simulation results. All these structures have been designed and simulated in CST MWS.

6 citations


Journal ArticleDOI
TL;DR: In this paper, a broadband and low-cost PAF element using cross-dipole antenna at L-band is designed based on the requirement of the FAST, which is fed by two microstrip baluns which have high performance and is easy to manufacture compared to the traditional coaxial balun.
Abstract: The Five-Hundred-Meter Aperture Spherical Telescope (FAST) is a Chinese megascience project that aims to build the largest single dish radio telescope in the world. Given its multiple simultaneous beam formation, phased array feed (PAF) is widely used to extend the field of view and enhance the survey speed of the radio telescope. In this study, a broadband and low cost PAF element using cross-dipole antenna at L-band is designed based on the requirement of the FAST. The antenna is fed by two microstrip baluns which have high performance and is easy to manufacture compared to the traditional coaxial balun. A simple system model is also introduced to evaluate the PAF performance. The measured results of the fabricated element and the simulations of the system performance validate the effectiveness of element design.

Journal ArticleDOI
TL;DR: It is proved to have better autocorrelation with a sharp main lobe and smaller side lobes, larger Gabor bandwidth, smaller Cramér–Rao lower bound, and less multipath error; more importantly, it can satisfy the threshold of leakage out of band.
Abstract: Because of the congestion of current navigation signals in the L band, the frequency band between 5010 and 5030 MHz allocated as C band with smaller ionospheric errors can be taken as a candidate band for global navigation satellite system (GNSS). The main objective of C band signal design is to achieve band limitation, compatibility, multipath resistance, satisfactory tracking, and acquisition performance. The minimum shift keying (MSK) chip waveform has been proven to be effective in providing better spectrum confinement and a constant envelope. However, the MSK chip waveform with an arbitrary binary coded symbol (BCS) may not meet the requirements of the C band. Thus, the BCS sequence ([s0,s1,⋯ ,sn − 1],fc) = ([1,1,1,1,−1,−1,1,−1,1,−1],1) is obtained by means of a thorough computer search for low autocorrelation side lobes based on a Neuman–Hofman code of length 10 with MSK pulses form MSK-BCS ([1,1,1,1,−1,−1,1,−1,1,−1],1). It is proved to have better autocorrelation with a sharp main lobe and smaller side lobes, larger Gabor bandwidth, smaller Cramer–Rao lower bound, and less multipath error; more importantly, it can satisfy the threshold of leakage out of band. It will be of great significance for signal design in C band. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Journal ArticleDOI
TL;DR: In this paper, the authors describe the theory for performing retrieval of radio occultations that use probing frequencies in the XK and KM band, which is based on the Doppler shift imposed by the atmosphere, on the signal emitted from the GPS satellite.
Abstract: This paper describes the theory for performing retrieval of radio occultations that use probing frequencies in the XK and KM band. Normally, radio occultations use frequencies in the L band, and GPS satellites are used as the transmitting source, and the occultation signals are received by a GPS receiver on board a Low Earth Orbit (LEO) satellite. The technique is based on the Doppler shift imposed, by the atmosphere, on the signal emitted from the GPS satellite. Two LEO satellites are assumed in the occultations discussed in this paper, and the retrieval is also dependent on the decrease in the signal amplitude caused by atmospheric absorption. The radio wave transmitter is placed on one of these satellites, while the receiver is placed on the other LEO satellite. One of the drawbacks of normal GPS-based radio occultations is that external information is needed to calculate some of the atmospheric products such as the correct water vapor content in the atmosphere. These limitations can be overcome when a proper selected range of high-frequency waves are used to probe the atmosphere. Probing frequencies close to the absorption line of water vapor have been included, thus allowing the retrieval of the water vapor content. Selecting the correct probing frequencies would make it possible to retrieve other information such as the content of ozone. The retrieval is performed through a number of processing steps which are based on the Full Spectrum Inversion (FSI) technique. The retrieval chain is therefore a wave optics-based retrieval chain, and it is therefore possible to process measurements that include multipath. In this paper simulated LEO to LEO radio occultations based on five different frequencies are used. The five frequencies are placed in the XK or KM frequency band. This new wave optics-based retrieval chain is used on a number of examples, and the retrieved atmospheric parameters are compared to the parameters from a global European Centre for Medium-Range Weather Forecasts analysis model. This model is used in a forward propagator that simulates the electromagnetic field amplitudes and phases at the receiver on board the LEO satellite. LEO-LEO cross-link radio occultations using high frequencies are a relatively new technique, and the possibilities and advantages of the technique still need to be investigated. The retrieval of this type of radio occultations is considerably more complicated than standard GPS to LEO radio occultations, because the attenuation of the probing radio waves is used in the retrieval and the atmospheric parameters are found using a least squares solver. The best algorithms and the number of probing frequencies that is economically viable must also be determined. This paper intends to answer some of these questions using end-to-end simulations.


Proceedings ArticleDOI
01 Aug 2016
TL;DR: A coplanar waveguide-fed quad-band monopole antenna is proposed and analyzed by using four meander lines for L-band, 2.4 GHz wireless local area networks (WLAN) and 3.5 GHz worldwide interoperability for microwave access (WiMAX) communication applications.
Abstract: A coplanar waveguide (CPW)-fed quad-band monopole antenna is proposed and analyzed by using four meander lines for L-band, 2.4 GHz wireless local area networks (WLAN)and 3.5 GHz worldwide interoperability for microwave access (WiMAX) communication applications. The desired quad frequency bands are generated by means of four meander lines. The simulation results indicate that the optimized CPW-fed quad-band monopole antenna can operate at 1.15–1.25 GHz and 1.5–1.9 GHz for L-band, 2.39–2.49 GHz for WLAN and 3.5 GHz for WiMAX communication applications with respect to S 11 < −10 dB. Additionally, the proposed antenna gives a good impedance matching characteristic and almost omnidirectional radiation patterns in the operation bands, making it suitable for multi-band wireless communication applications.

Proceedings Article
01 Oct 2016
TL;DR: In this paper, a two-port, dual-band antenna element for wide-angle scanning planar phased array is designed, which consists of two parts: the annular slot fed by a microstrip line and a circular patch fed by an H shaped slot.
Abstract: Two-port, dual band antenna element for wide-angle scanning planar phased array is designed. The antenna element consists of two parts: the annular slot fed by a microstrip line and a circular patch fed by an H shaped slot. The annular slot is used to operate over the L-band and the circular patch over the S radar band. The antenna element demonstrates dual-band performance with sufficient bandwidth in both bands and consistent radiation patterns. Due to its small dimensions, the element is well-suited for application to wide-scan phased arrays in multiscale configuration.

Book ChapterDOI
01 Jan 2016
TL;DR: In this paper, the authors proposed a dual-band antenna for radar communication with the working frequency of 1.55 GHz and 6 GHz and it was designed on a Rogers RT/Duroid 6202 laminate substrate (dielectric constant = 2.2).
Abstract: We have proposed the design, performance and analysis of a novel dual band antenna for radar communication. The working frequency of the antenna is 1.55 and 6 GHz and it is designed on a Rogers RT/Duroid 6202 laminate substrate (dielectric constant = 2.2). The length and width of the patch are respectively 15 and 20 mm, while the length (l) and width (w) of the slots are respectively 14 and 1 mm with a 10 mm feed length. We have used IE3D Zealand (Ver-12) for obtaining the simulation result and analysis of our proposed antenna. The results are analyzed by investigating current distribution, S(1,1), elevation pattern, directivity pattern and voltage standing wave ratio (VSWR). Our antenna finds both L band (1–2 GHz) and C band (4–8 GHz) applications where it can be effectively used for RADAR application.


Journal ArticleDOI
TL;DR: In this paper, a novel design of high and broad gain that covers C and L bands is demonstrated experimentally, which combines two double pass with split band structure, where signals travel in separate paths after being splitted using a coupler band splitter.
Abstract: A novel design of high and broad gain that covers C and L bands is demonstrated experimentally. The techniques, used in this paper, combine two double pass with split band structure. The signals travel in separate paths after being splitted using a coupler band splitter. The topology of this new configuration uses this technique to broaden the gain at its maximum range of amplification. The presented paper is to study the performance of the augmented gain of the EDFA configuration using what it can be called double pass wide band amplification. The results show a broadening range of 80 nm between 1520 nm and 1600 nm in the C and L band and high gain of 45 dB for the range 1525 nm and 1580 nm and lower gain for the range 1580 nm and 1600 nm. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2093–2096, 2016

Book ChapterDOI
09 Nov 2016
TL;DR: A theoretical model for a land mobile satellite channel is analyzed in various shadowing situations, and a kind of asymmetrical Doppler power spectrum is proposed in order to effectively respond to the actual channel environment.
Abstract: Comparing with the traditional mobile communication system, there is a strong line-of-sight (LOS) component in satellite to mobile communication. In fact, LOS and diffuse scattered component are both influenced by shadowing and obstacles. In this paper, a theoretical model for a land mobile satellite channel is analyzed in various shadowing situations. Since LOS and diffuse scattered component are both considered, the angles of arrival are not uniformly distributed in a given azimuth sector. So a kind of asymmetrical Doppler power spectrum is proposed in the paper. Then, in order to effectively respond to the actual channel environment, the different state length \( L_{frame} \) in each state is presented and simulated, the minimum state length should be shorter in the environment, which the channel changes intensely. Finally, numerical simulations in four-state Markov model indicate that the proposed asymmetrical Doppler power spectrum and the various \( L_{frame} \) are reasonable.

Proceedings ArticleDOI
01 Sep 2016
TL;DR: In this article, a 5-bit digital phase shifter for L-band SAR is designed using delay line topology and PIN diode switches, which is used to control each antenna's phase.
Abstract: PALSAR (Phased Array L-Band SAR) is a kind of L-Band SAR (Synthetic Aperture Radar) with each antenna in the system is varied by its phase to improve its performance. The PALSAR works in 1.27 GHz with varying bandwidth according to specified PALSAR system. Phased shifter is used to control each antenna's phase. Phase shifter is designed for specified frequency to reach better performance than usual phase shifter. In this paper, 5 bit digital phase shifter for L-Band SAR is designed using delay line topology and PIN diode switches. The result shows RMS error less than 2°, return loss more than 10 dB and insertion loss less than 0.8 dB.

Journal ArticleDOI
TL;DR: In this article, a fundamental investigation is carried out to explore the Ku/V band as a candidate frequency band for a new global satellite navigation carrier signal, wherein specific attention is given to the effects of the dominant attenuation factors through the tropospheric propagation path.
Abstract: For next generation global navigation satellite systems, new carrier frequencies in Ku/V band are expected to emerge as a promising alternative to the current frequency windows in L band as they get severely congestive. In the case of higher frequency bands, signal attenuation phenomenon through the atmosphere is significantly different from the L band signal propagation. In this paper, a fundamental investigation is carried out to explore the Ku/V band as a candidate frequency band for a new global satellite navigation carrier signal, wherein specific attention is given to the effects of the dominant attenuation factors through the tropospheric propagation path. For a specific application, a candidate orbit preliminarily designed for the Korean regional satellite navigation system is adapted. Simulation results summarize that the Ku band can provide a promising satellite navigation implementation considering the present satellite’s power budget, while the V band still requires technical advances in satellite transceiver system implementations.

Proceedings ArticleDOI
10 Jul 2016
TL;DR: A modified Physical Optics (PO) approximation model and a specified Discrete Dipole Approximation (DDA) model have been developed that involves parabolic leaf curvature effects that presents the maximum accuracy in >84% testing cases, and retains the high accuracy in both the low and high frequency band.
Abstract: Rice leaf scattering contributes substantially to total vegetation canopy backscattering. A modified Physical Optics (PO) approximation model and a specified Discrete Dipole Approximation (DDA) model have been developed that involves parabolic leaf curvature effects. Three typical leaves are chosen among 1433 pieces of parabolic leaves sampled in a ground measurement. PO, DDA, Generalized Rayleigh Gans (GRG) approximation, were used to calculate the leaf scattering, respectively. The method of moments (MOM), a computational electromagnetic method, is utilized to evaluate each models' accuracy. Validation work is conducted under the incidence angles 10° ∼ 60°, incidence azimuthal angle 0° ∼ 360°, incident frequencies L Band (1.2 GHz), C Band (5.4 GHz) and X Band (9.65 GHz). Compared with DDA and GRG, the modified PO model presents the maximum accuracy in >84% testing cases, and retains the high accuracy in both the low and high frequency band.


Patent
27 Jul 2016
TL;DR: In this article, a multi-band antenna with a plurality of antenna radiating elements comprising a VHF band antenna, an S band antenna and an L band antenna is presented.
Abstract: The present invention discloses a multi-band antenna. The multi-band antenna is provided with: a plurality of antenna radiating elements comprising a VHF band antenna, an S band antenna, and an L band antenna, which are used to radiate radio electromagnetic energy to space and receive radio electromagnetic energy; an L band feeding unit, used to feed the L band antenna; an S band feeding unit, used to feed the S band antenna; an S band diplexer unit, used to achieve high isolation between receiving and sending by the S band antenna, wherein the VHF antenna element is electrically connected to the S band feeding unit; and a VHF antenna multi-frequency matching unit, used for multi-frequency matching of the VHF band antenna. The multi-band antenna disclosed by the present invention has the following advantages that the antennas are combined and arranged in vertical space according to radiation characteristics of the antennas, so that electromagnetic radiation of the antenna of each band is in a required spatial direction, signals of each frequency can be effectively transmitted and received, and a feed circuit of each band can perform effective feeding for each band, providing line-of-sight, middle-distance, and long-distance alerts, reports, and voice communication.

Proceedings ArticleDOI
01 Jul 2016
TL;DR: The design of a narrow band cavity filter in L band with centre frequency of 1575.42 MHz is planned to use at the front end of a GPS receiver where the system has to withstand the harsh environment of launch vehicle.
Abstract: Filters play a critical role in RF and Microwave systems and the type used depends on the application. It is used in the receiver front end to improve selectivity and in transmitter for spurious /harmonic rejection where low insertion loss and narrow bandwidth are the major requirements. This paper, deals with the design of a narrow band cavity filter in L band with centre frequency of 1575.42 MHz. It is planned to use at the front end of a GPS receiver where the system has to withstand the harsh environment of launch vehicle. The cavity filter is designed for the required specification, simulated and optimized using the software Advanced Design System (ADS) and ElectroMagnetic Professional (EMPro).

Journal ArticleDOI
TL;DR: In this article, a varactor-loaded dual-band resonator comprised of series and parallel LC circuits is employed in the load circuit of differential amplifiers for realizing dualbandstop responses as well as the series feedback circuit for dualbandpass responses.
Abstract: L-band SiGe HBT dual-band differential amplifiers with frequency-tunable bandpass or bandstop responses have been developed for the next generation adaptive and/or reconfigurable wireless radios. A novel varactor-loaded dual-band resonator comprised of series and parallel LC circuits is employed in the load circuit of differential amplifiers for realizing dual-bandstop responses as well as the series feedback circuit for dual-bandpass responses. The dual-bandstop amplifier has presented a lower-bandstop frequency of 0.47 to 0.62 GHz with an upper-bandstop frequency of 1.17 to 1.18 GHz. Meanwhile, an upper–bandstop frequency can be varied from 0.6 to 1.1 GHz for a lower-bandstop frequency of 0.37 to 0.4 GHz. The maximal band-rejection was 17.7 dB. In addition, the dual-bandpass amplifier has achieved a lower-bandpass frequency of 0.37 to 0.5 GHz with an upper-bandpass frequency of 0.61 to 0.63 GHz. Meanwhile, an upper714 Yasushi Itoh and Hiroaki Takagi bandpass frequency can be varied from 0.61 to 1.11 GHz for a lower-bandpass frequency of around 0.36 GHz. The maximal gain was 9.6 dB. The varactor-loaded dual-band resonator presented in this paper is expected to be one candidate for realizing the multi-band amplifier utilized in the reconfigurable wireless transceivers.

Proceedings ArticleDOI
01 Dec 2016
TL;DR: This paper presents design studies of three layer high impedance surface for three different structures (prototypes) with and without vias for L band application.
Abstract: This paper presents design studies of three layer high impedance surface for three different structures (prototypes) with and without vias for L band application. High impedance surface zero reflection phase and surface wave band and current density are few important aspects taken into consideration for comparing three HIS structures for different antenna applications. Transverse electric and transverse magnetic modes are realized from dispersion diagram. Dispersion diagram of three HIS structures is realized by Eigen mode solver. Design and simulation of three layers HIS is performed using CST v.15.

Proceedings ArticleDOI
01 Mar 2016
TL;DR: In this article, an ultra-wide tuning range filtering antenna is proposed in which the frequency tuning range is from 200 MHz to 1.8 GHz which covers from P to L bands by a varactor and two singlepole-doube-throw switches.
Abstract: An ultra-wide tuning range filtering antenna is proposed in this paper. The frequency tuning range is from 200 MHz to 1.8 GHz which covers from P to L bands by a varactor and two single-pole-doube-throw switches. The switches controls two groups of inductors which corresponding to two frequency tuning range. The filtering antenna has high selectivity and low insertion loss and very wide frequency tuning range.

Proceedings ArticleDOI
10 Jul 2016
TL;DR: A highly efficient method, the stochastic second degree iterative algorithm with sparse matrix and Chebyshev approximation (SSD-SM-Cheby), for the analysis of fully polarimetric bistatic scattering behavior from the interaction of electromagnetic wave with all scales of ocean waves at L band is developed.
Abstract: With the rising interest in exploring the possibility of estimating geophysical parameters of interest to oceanographers by global navigation satellite system reflectometry (GNSS-R) of signals scattered from the ocean surface, and the advent of the Soil Moisture Active Passive (SMAP) [1] and the Soil Moisture and Ocean Salinity (SMOS) [2] scientific missions, there is a need to understand the relevant scattering physics at L band so as to provide a physical basis for retrieving geophysical information from ocean-scattered signals.