In this paper, we have presented the simulation results of a rectangular microstrip patch antenna at terahertz (THz) frequency ranging from 0.7 to 0.85 THz. THz electromagnetic wave can permit more densely packed communication links with increased security of communication transmission. The simulated results such as gain, radiation efficiency and 10 dB impedance bandwidth of rectangular microstrip patch antenna at THz frequencies without shorting post configuration are 3.497 dB, 55.71% and 17.76%, respectively, whereas with shorting post configuration, corresponding parameters are 3.502 dB, 55.88% and 17.27%. The simulation has been performed by using CST Microwave Studio, which is a commercially available electromagnetic simulator based on the method of finite difference time domain technique.

Rectangular Microstirp Patch Antenna Design at THz Frequency for Short Distance Wireless Communication Systems

A low-profile wideband circularly polarized (CP) crossed-dipole antenna that has both wide axial-ratio beamwidth (ARBW) and half-power beamwidth (HPBW) is presented in this paper. The crossed dipoles are composed of four trapezoidal patch arms, and they are fed by a pair of vacant-quarter printed rings to generate CP radiation. Four identical parasitic elements that consist of a horizontal triangle patch and a vertical metallic plate are symmetrically intervened between the crossed dipoles and the ground plane. It has been found that the parasitic elements can effectively decrease the antenna profile, increase the operating bandwidth, and simultaneously enhance the ARBW as well as the HPBW. A prototype was fabricated and measured to verify the design. The measured results show that the prototype has a low profile of $0.1\lambda _{0}$ , a −10 dB impedance bandwidth of 78.3% and a 3 dB AR bandwidth of 63.4%. Moreover, a 3 dB ARBW of more than 120° and an HPBW of more than 110° are achieved simultaneously within a wide passband of 50.7%.

A Low-Profile Wideband Circularly Polarized Crossed-Dipole Antenna With Wide Axial-Ratio and Gain Beamwidths

A low-profile crossed dipole antenna with wide bandwidth is investigated in this letter. The double-sided printing crossed dipoles consisting of four-stepped rectangular patches are fed by a pair of vacant-quarter printed rings, generating circularly polarized radiation. Two adjacent axial-ratio (AR) passbands with AR < 3 dB are generated due to the stepped rectangular patches, and they are merged together by adding an additional dielectric slab above the ground plane, resulting in a very wide AR bandwidth. Also, an irregular ground plane is used for the antenna, which can desirably enhance the boresight gain without involving high-profile cavity. To verify the feasibility of the proposed design, a prototype operating at C-band has been fabricated and measured. Reasonable agreement between the simulated and measured results is obtained. The prototype has a low profile of 0.13 λ0 (in terms of the center frequency of passband), a 10-dB impedance bandwidth of 66.9%, a 3-dB AR bandwidth of 55.1%, and an average gain of approximately 10.4 dBic within passband.

A Low-Profile Wideband Circularly Polarized Crossed-Dipole Antenna

Proximity-coupled two-port multi-input-multi-output graphene antenna with pattern diversity for THz applications

A review paper concerning wide-band and ultra-wideband (UWB) antennas used for wireless communication purposes in terms of the materials as well as a numerical analysis is presented. These antennas which are taken into account are listed as wide-band microstrip antenna, wide-band monopole antenna over a plate, wide-slot UWB antenna, stacked patch UWB antenna, taper slot (TSA) UWB antenna, metamaterial (MTM) structure UWB antennas, elliptical printed monopole UWB antenna, and flexible wearable UWB antenna. The antennas’ performance is compared based on their size and how they can be applicable for portable communication device applications. This review paper furnishes a proper direction to select varieties of figures in terms of impedance bandwidth, gain, directivity, dimensions, time domain characteristics, and materials affecting these antenna’s characteristics.

/pdf/ultra-wideband-antennas-for-wireless-communication-ce0j6biyt7.pdf

Ultra-Wideband Antennas for Wireless Communication Applications

A singly-fed wideband circularly polarized dielectric resonator antenna is proposed in this communication. Antenna structure contains a rectangular and two half split cylindrical dielectric resonators. Multiple orthogonal modes are excited in the antenna structure when excitation is applied through a stair-shaped slot. Measured results show that antenna provides wider 3-dB axial ratio and impedance bandwidths of 41.01% and 49.67%, respectively. Proposed antenna can be utilized in C-band applications.

Wide Band Circularly Polarized Dielectric Resonator Antenna With Stair-Shaped Slot Excitation

A multiband dielectric resonator (DR) antenna is proposed with dual-band circularly polarized (CP) response. This antenna consists of an inverted-sigmoid shaped DR. A metallic strip is applied at the surface of the DR to achieve the circular polarization. The fundamental and higher order hybrid modes are excited in the antenna structure because of the specific geometry. The antenna with dual-band CP response provides the measured 3 dB axial ratio (AR) bandwidth of 19.98% in the lower band and 3.07% in the upper band. The upper band 3 dB AR response can be tuned in different 10 dB impedance passbands of the antenna by changing the location and width of the metallic strip. Antenna response can also be tuned to obtain the triple band CP operation.

Inverted-Sigmoid Shaped Multiband Dielectric Resonator Antenna With Dual-Band Circular Polarization

An annular dielectric resonator (DR) antenna (DRA) is implemented for THz applications. A silicon made DR is loaded with graphene disk for obtaining the tunability in the frequency response. The physical parameters of silicon annular DR can be set to obtain the resonance at any frequency in the lower THz band and can be tuned by changing the chemical potential of graphene nano-disk placed at the top of the DR. The response of antenna is preserved after changing the chemical potential of graphene. The higher order hybrid electromagnetic mode is excited in the antenna structure. The proposed research work provides a way to implement the antenna for THz frequency with high gain around 3.8 dBi and radiation efficiency in the range 72 − 75%.

Tunable Terahertz Dielectric Resonator Antenna

A reconfigurable graphene antenna is designed and numerically analyzed. The antenna structure contains a radiating graphene patch and non-radiating graphene ring. The operating frequency of the antenna can be tuned by applying the gate voltage on the graphene patch. This proximity coupled antenna structure operates with the [Formula: see text] mode. In this configuration, the field is distributed in the form of horizontal magnetic dipole. The application of gate voltage at the periphery of graphene ring converts the field configuration to the form of the vertical electric dipole. Thus, the mode of operation of the antenna is changed to [Formula: see text] Consequently, the radiation pattern of the antenna can be steered in different directions as per the location of the applied gate voltage at the periphery of the graphene ring.

Gaurav Varshney

Papers

Wide Band Circularly Polarized Dielectric Resonator Antenna With Stair-Shaped Slot Excitation

Proximity-coupled two-port multi-input-multi-output graphene antenna with pattern diversity for THz applications

Inverted-Sigmoid Shaped Multiband Dielectric Resonator Antenna With Dual-Band Circular Polarization

Tunable Terahertz Dielectric Resonator Antenna

Reconfigurable graphene antenna for THz applications: a mode conversion approach.