X-band Downlink Satellite Communication Research Articles

An ultrawideband antenna with two independently tunable notch bands

This paper presents a planar CPW-fed Ultrawideband (UWB) antenna with two independently tunable notch bands. The proposed design consists of a modified Rhombus-shaped monopole structure that is integrated with a dual band-stop filter based on hexagonal split ring resonators (HSRR). The antenna is capable of suppressing multiple frequency bands within ultrawideband range (3.1–11 GHz) such as WLAN and X-band downlink satellite communication frequency bands with an independent tunable mechanism to fulfill the on-demand band rejection. The frequency reconfigurability of the two notch bands is obtained by loading the hexagonal filter arms with two varactor diodes (for each band). Details of antenna design steps and reconfigurability mechanism are illustrated. The notch band element is explained using equivalent circuit model and surface current distribution at lower and higher notch frequency bands. A prototype of the proposed design is printed on the RO4003C (ϵr = 3.55) substrate printed circuit board (PCB) and tested to authenticate the performance. The proposed antenna volume is 21.5 ▪ 48 ▪ 1.524 mm3 and demonstrates an omnidirectional radiation pattern in E and H planes with an average gain of 3.7 dBi across the operational passbands, while a sharp reduction in gain of -6.8 dBi and -3.5 dBi is achieved at the lower and higher notch bands, respectively. Continuous tuning is achieved experimentally from 5.08 to 5.77 GHz and 7.75 to 8.52 GHz for the lower and higher notch bands, respectively. Excellent agreement is observed between the simulated and measured results. Application areas include radio-frequency identifications, ground-penetrating radar, and wireless communications.

Compact UWB MIMO antenna with dual band-notch characteristics

ABSTRACT This article describes a quad-port ultra-wideband multiple-input multiple-output (MIMO) antenna with dual-band notch characteristics that is very compact and highly isolated. The compactness and high isolation of this design are achieved by etching a modified Minkowski fractal structure and an inverted L-shaped stub made available by the partial ground plane. Simply by incorporating ‘C’- and ‘U’-shaped slots in the radiating patch, it is possible to obtain dual-band rejection characteristics that are very suitable for wireless local area network band and X-band downlink satellite communication of 5.0–5.9 GHz and 7.1–7.9 GHz, respectively, in this proposed structure. The entire design is housed in a very compact size of 30 mm × 30 mm. A few key parameters, such as channel capacity loss (CCL), envelope correlation coefficient (ECC), diversity gain (DG) and total active reflection coefficient (TARC), are examined to ensure that the MIMO system meets its requirements. Furthermore, a mutual coupling value of less than −22 dB and an operating frequency band of 3.1–12 GHz allow the design to be very effective in a multipath channel environment.

A wideband compact antenna with quad‐circular polarized bands in its operating regions

This article presents the design of an offset CPW-fed slot antenna which exhibits a narrow impedance bandwidth (IBW; |S11| ≤ −10 dB) extending from 1.20 GHz to 1.45 GHz and another wide impedance bandwidth from 1.86 GHz to 8.4 GHz thus covering almost all the conventional operating frequencies. The antenna is loaded with semicircular and rectangular stubs and meandered microstrip lines to realize circular polarization at 1.35 GHz, 3.3 GHz, 4.9 GHz, and 7.5 GHz with axial ratio bandwidth (axial ratio ≤ 3 dB) of 19.25% (1.2-1.46 GHz), 4.24% (3.24-3.38 GHz), 4.1%(4.8-5 GHz), and 5.2% (7.3-7.69 GHz) respectively thus covering the GPS, WiMAX, WLAN, and X-band downlink satellite communication application bands. The mechanism of generation of CP is discussed using vector analysis of surface current density distribution. The gain is fairly constant in the wide IBW region with maximum fluctuation of 1.2 dB. The structure is compact with an overall layout area of 0.27λ × 0.27λ, where λ is the free-space wavelength corresponding to the lowest circular polarized (CP) frequency. A comparison of the proposed antenna with previously reported structures is performed with respect to impedance bandwidth, compactness, number of CP bands, LHCP to RHCP isolation and gain to comprehend the novelty of the proposed design. A prototype of the proposed antenna is fabricated and the measured results are in accord with the simulated results.

Analysis and design of a compact ultra-wideband antenna with WLAN and X-band satellite notch

<span lang="EN-US">A compact design of ultra-wideband (UWB) antenna with dual band-notched characteristics based on split-ring resonators (SRR) are investigated in this paper. The wider impedance bandwidth (from 2.73 to 11.34 GHz) is obtained by using two symmetrical slits in the radiating patch and another slit in the partial ground plane. The dual band-notch rejection at WLAN and X-band downlink satellite communication system are obtained by inserting a modified U-strip on the radiating patch at 5.5 GHz and embedding a pair of rectangular SRRs on both sides of the microstrip feed line at 7.5 GHz, respectively. The proposed antenna is simulated and tested using CST MWS high frequency simulator and exhibits the advantages of compact size, simple design and each notched frequency band can be controlled independently by using the SRR geometrical parameters. Therefore, the parametric study is carried out to understand the mutual coupling between the dual band-notched elements. To validate simulation results of our design, a prototype is fabricated and good agreement is achieved between measurement and simulation. Furthermore, a radiation patterns, satisfactory gain, current distribution and VSWR result at the notched frequencies make the proposed antenna a suitable candidate for practical UWB applications.</span>

Multi-Band Notched Antennas for UWB Applications

A compact ultra-wideband circular monopole antennas with single, dual, triple and quad-band rejection characteristics are proposed in this paper. The antenna units are designed using RT/DUROID substrate with permittivity 2.2 and all are fed through a coplanar waveguide (CPW). In the proposed antennas splitted concentric rings (SCR) are used to achieve band rejection characteristics. The proposed antennas will reject the existing WLAN (Wireless Local Area Network), WiMAX (World Wide Interoperability for Microwave Access), X-band downlink satellite communication and radio-frequency channel arrangements for fixed wireless systems to avoid interference. Simulations are carried out using CST Wave Studio Suite 2016. Antenna performance parameters like return loss, VSWR, radiation pattern and gain are evaluated for all the antenna units. The antenna units having dimensions of 30×23×1.57 mm3 are fabricated and tested. The simulated and tested results are compared and reported. These antenna units provide good gain and a larger bandwidth over the frequency range 3–11.6 GHz.

Compact dual polarised CDRA with stimulation of triple radiating mode

ABSTRACTIn this communication, compact cylindrical dielectric resonator antenna (CDRA) is designed and examined with diversified polarisation features in twofold frequency ranges. Three significant features of proposed CDRA are: (i) modified circular shaped aperture is used to stimulate the CDRA, which helps to excite triple radiating modes inside it i.e. HEM11δ, HEM12δ, HEM13δ; (ii) proposed CDRA supports two different polarisation features i.e. Linear as well as circular; (iii) modified circular aperture makes the CDRA electrically compact approximately by 14%. Fabricated prototype of proposed CDRA is used to practically authenticate the results. After measurement, it approves that the proposed CDRA is working in twofold frequency bands i.e. 4.83–6.82 GHz and 7.05–7.52 GHz with the percentage bandwidth of 34.19 and 6.45%, respectively. Experimental results also approve that the proposed CDRA support circularly polarised waves during frequency range 5.65–6.25 and 7.2–7.52 GHz, respectively. Stable far-field results confirm its suitability for WLAN (5.0 GHz) and X-band downlink satellite communication band (7.0 GHz).

Design and analysis of triple notch ultrawideband antenna using single slotted electromagnetic bandgap inspired structure

ABSTRACTA microstrip line fed pentagonal printed ultra wideband (UWB) monopole antenna with partial ground plane having triple notches is proposed. The realized antenna has an operating bandwidth (VSWR ≤ 2) ranging from 3.1 GHz and continuing beyond 12 GHz. A novel mushroom-shaped slotted electromagnetic bandgap (EBG) inspired structure is used near the feedline to introduce triple notches at CBRS (3.5–3.7) GHz, WLAN (5.15–5.725) GHz and X-band downlink satellite communication (7.25–7.75) GHz frequencies. The band notch characteristics are demonstrated with current distribution and impedance analysis. Further, the proposed structure has stable radiation patterns, gain and group delay in the UWB range except the notch frequencies. Finally, a prototype of the proposed antenna is fabricated and measured results are in good agreement with the simulated results.

Study on frequency and impulse response of novel triple band notched UWB antenna in indoor environments

In this paper, a novel fork shaped structure backed plane is added to a simple UWB (ultra wideband) slot antenna to enhance the impedance bandwidth as well as create triple band notched characteristics for Impulse Radio (IR) UWB applications. This fork-shaped structure is connected to a rectangular radiating patch at four different points through the cylindrical pins. The proposed antenna with this fork-shaped structure shows a very wide impedance bandwidth which spans from 2.5 up to more than 20 GHz and offers triple band-notched properties in WiMAX, WLAN and X-band downlink satellite communication spectrums. Moreover, the proposed antenna shows good radiation features such as gain, radiation efficiency and radiation patterns. A comprehensive investigation on the antenna time domain performance is also performed throughout the paper, and the effect of the proposed antenna on the two popular excitation pulses including modulated Gaussian (MG) and square root raised cosine (SRRC) pulses is fully investigated. A frequency-domain measurement setup is applied to measure time domain characteristics of the proposed antenna. Also, the realistic indoor multipath propagation channel characteristics when the proposed antennas are applied as the transmitter and receiver antennas are studied. Sub-band divided ray tracing method is used to simulate channel characteristics.

Time-domain analysis of compact dual band-notched slot antenna in indoor environments

AbstractFrequency- and time-domain characteristics as well as indoor propagation channel impulse response of a compact dual band-notched ultra-wideband (UWB) slot antenna are investigated in this paper. The antenna consists of a narrow rectangular radiation patch and a rectangular wide slot in the modified ground plane. A pair of L-shaped stubs are connected to the radiation patch to obtain band-notched property in WLAN band and a narrow straight stub is placed on the back side of the substrate to create band-notched characteristics in X-band downlink satellite communication system. Moreover, two small parasitic strips are added to the radiation patch to enhance the bandwidth (BW) of the antenna up to 14 GHz. A comprehensive study on time-domain and indoor propagation channel characteristics of the proposed antenna is also presented throughout the paper. A ray-tracing approach based on geometrical optics is applied to analyze the indoor channel characteristics. The designed antenna not only has a wide BW and compact size but also has appropriate radiation and time-domain characteristics over the antenna operating BW. The measured and simulated results are in good agreement. These advantages make the proposed antenna as a desirable option for UWB impulse radio applications.

Triple band notched mushroom and uniplanar EBG structures based UWB MIMO/Diversity antenna with enhanced wide band isolation

Triple band-rejection MIMO/Diversity UWB antenna characteristics are described in this paper. Proposed antenna discards worldwide interoperability for microwave access WiMAX band from 3.3 to 3.6 GHz, wireless local area network WLAN band from 5 to 6 GHz and X-Band satellite downlink communication band from 7.1 to 7.9 GHz. Mushroom Electromagnetic Band Gap (EBG) structures helps to attain band notches in WiMAX and WLAN bands. Uniplanar plus shaped EBG structure is used for notch in X-band downlink satellite communication band. Decoupling strips and slotted ground plane are employed to develop the isolation among two closely spaced UWB monopoles. The individual monopoles are 90° angularly separated with stepped structure which helps to reduce mutual coupling and also contributes towards impedance matching by increasing current path length. Mutual coupling magnitude of more than 15 dB is found over whole UWB frequency range. The Envelope Correlation Coefficient is less than 0.02 over whole UWB frequency range.The variations in the notched frequency with the variations in mushroom EBG structure parameters are investigated.The antenna has been designed using FR-4 substrate and overall dimensions is (64 × 45 × 1.6) mm3.

Printed Ultrawideband Monopole Antenna with Four Notch Band

A compact ultra-wideband planar monopole antenna with four notched bands is proposed. The antenna consists of a rectangular radiating patch with two bevels at lower edge and a modified ground plane with two bevels at upper edge. In order to realize multiple notch characteristics in the WiMAX band (3.3---3.7 GHz), the lower WLAN band (5.15---5.35 GHz), and higher WLAN band (5.725---5.875 GHz), three round shape slots are inserted in radiating patch. The fourth notch band in X-band downlink satellite communication band (7.1---7.76 GHz) is obtained by etching a pair of C-shaped slots in the ground. The proposed antenna exhibits a nearly omnidirectional radiation pattern in the H-plane, and a dipole-like radiation pattern in the E-plane for the for the entire pass band. The measured operating impedance bandwidth of proposed antenna ranges from 3.1 to more than 17 GHz having reflection coefficient magnitude less than ?10 dB with four notched bands. The effects of each individual slot on band notch characteristics are also investigated. The measured gain of the proposed quad band notched antenna is relatively stable across the operating frequency band except notched bands and thereby making the proposed antenna suitable for practical UWB applications. Proposed antenna has a compact size of 30 × 26 mm2.

A compact triple band notch circular ring antenna for UWB applications

In this article, a study of a triple band notched circular ring monopole ultrawide band (UWB) antenna is presented. The UWB antenna consists of a circular ring radiating patch and rectangular ground plane with two small slots near the feed line for bandwidth enhancement. The proposed antenna can reject worldwide interoperability for microwave access (WiMAX) band (3.3–3.8 GHz), wireless local area network (WLAN) band (5–6 GHz) and X-band downlink satellite communication band (7.1–7.9 GHz). The WiMAX and WLAN band rejections are realized by introducing two arc shaped elliptical slots and single elliptical split ring slot in the radiating patch, respectively. Furthermore, a pair of rectangular single split ring resonators is used to obtain the rejection of X-band downlink satellite communication signal. The proposed UWB antenna is fabricated and measured. The measured results are in good agreement with the simulated ones. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:668–672, 2015

A Triple Band Notch Compact UWB Printed Monopole Antenna

A compact ultra-wideband planar monopole antenna with triple band-notched characteristic is proposed. The antenna consists of a rectangular patch with two bevels. To realize notch characteristics in 3.3---3.7 GHz for WiMax, and in 5.15---5.85 GHz for WLAN band, two round shape slots are etched in radiating patch. The third notch band in 7.1---7.76 GHz for X-band downlink satellite communication is obtained by etching a pair of C-shaped slot on the ground. The proposed antenna exhibits a nearly omnidirectional radiation pattern in the $$H$$H-plane, and a dipole-like radiation pattern in the $$E$$E-plane for the entire pass band. The proposed antennas are successfully simulated and measured. The individual effects of the each slot on band notch characteristics are also investigated. The gain of the proposed triple band notched antenna is relatively stable across the operating frequency band except at notched bands and thereby making the proposed antenna suitable for practical UWB applications.

PLANAR ULTRAWIDEBAND MONOPOLE ANTENNA WITH TRI-NOTCH BAND CHARACTERISTICS

In this article, a compact ultra-wideband (UWB) planar monopole antenna with the triple notched band is proposed. The antenna consists of a semicircular radiating patch and a modifled ground plane with two bevels at upper edge. By etching two round shape slots in radiating patch the notch characteristics are achieved at WiMax band (3.3{3.7GHz) and WLAN band (5.15{5.875GHz). In order to realize notch band at X-band downlink satellite communication band (7.1{7.76GHz) a pair of rotated V-shape slot are etched on the ground plane. The measured operating impedance bandwidth of proposed antenna ranges from 2.9 to 10.9GHz having return loss less than 10dB with triple notched bands. The proposed antenna exhibits a nearly omnidirectional radiation pattern in the H-plane, and a dipole-like radiation pattern in the E-plane for the ultra-wideband. The efiects of each individual slot on band-notch characteristics are also investigated. The measured gain of the proposed triple band notched antenna is relatively stable across the operating frequency band except notched bands and thereby making the proposed antenna suitable for practical UWB applications. Proposed antenna has a compact size of 27 £ 25mm 2 .