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Reconfigurable Printed Antennas
Published in Binod Kumar Kanaujia, Surendra Kumar Gupta, Jugul Kishor, Deepak Gangwar, Printed Antennas, 2020
Deepak Gangwar, Sachin Kumar, Surendra Kumar Gupta, Ghanshyam Singh, Ankit Sharma
Figure 9.11 shows the return loss of antenna without CSRR for different horizontal length of L-strip. The graph gives a very clear idea about the resonance frequencies due to L-strip and basic patch. As patch antenna feed length increases, the associated capacitance increases, causing the reduction in the upper resonant frequency. It is also interesting to see that the strip length may be varied to tune the antenna for various applications. The behavior of antenna return loss v/s frequency loaded with CSRR is shown in Figure 9.12. It is very similar to an unloaded antenna except the shift in resonant frequency. In an unloaded antenna, the theoretically calculated upper and lower resonances are at 3.83 GHz and 1.83 GHz, which have been shifted at 3.32 and 1.77 GHz, respectively, after loading CSRR (all theoretical values). That shows that a significant reduction in size is obtained.
Satellite Radio Antennas
Published in Victor Rabinovich, Nikolai Alexandrov, Basim Alkhateeb, Automotive Antenna Design and Applications, 2010
Victor Rabinovich, Nikolai Alexandrov, Basim Alkhateeb
A microstrip patch antenna consists of a very thin metallic patch placed above the conducting ground plane. The patch and ground plane are separated by a dielectric with constant εr. The simplest microstrip geometry of the half wave linear polarized rectangular patch is shown in Figure 7.3a. The length L, width W, and thickness h are the major parameters. A coaxial connector and RF coaxial cable provide the antenna feed (Figure 7.3b). The patch is printed on the top side of the dielectric substrate and the bottom of the board is the ground. The amplifier of the active patch antenna is mounted under the ground of the patch. The patch provides CP wave reception. The feeding probe operates as a monopole and together with the patch receives the VP wave from the low elevation angles (Reference [1], p. 60]. The SDARS antenna design includes only one low noise amplifier (LNA) and therefore only one output is connected to a receiver. The current typical SDARS antenna for automotive use is a rectangular patch.
On-Body Low-Profile Compact AMC-Integrated Wideband Antenna for Body Area Network Applications
Published in IETE Technical Review, 2023
The antenna feed structure is calculated in Equations (1)–(7). The width of the CPW strip (W), gap (g), thickness (h), and dielectric constant (ϵr) of the substrate determine the effective dielectric constant (ϵeff) and characteristic impedance (Z0) of the CPW line. The effective dielectric constant and characteristic impedance (Z0) of a coplanar waveguide on a dielectric substrate of finite thickness [31, 32] are given by k1 and k2 can be defined from the W, g and h parameters.
3D prism shaped circularly polarised MIMO diversity antenna with 360o angular coverage
Published in International Journal of Electronics Letters, 2022
Prashant Chaudhary, Ashwani Kumar, Kamlesh Patel, Ravi Kumar Arya, Maifuz Ali, A.K. Verma
The presented prism-shaped MIMO antenna is designed in six subsequent steps named step-1 to step-5 (see Figure 3). Evolution from a simple square shape (step-1) to a quadrilateral shape monopole (step-4) is shown in Figure 3a to 3d. The proposed antenna’s design process starts from step-1, a simple square patch whose dimensions can be obtained from equation-1. Where fs is the specified centre frequency of the truncated antenna-4 and fd is the frequency of the designed antenna. The free space wavelength is where c is the velocity of light, and we can obtain the length (L) of the patch by using equation-2 where, . The microstrip antenna feed is slightly off by 0.5 mm from the centre to get better impedance matching.
Design of 1*4 Microstrip Antenna Array on the Human Thigh with Gain Enhancement
Published in IETE Journal of Research, 2021
M. Mohammadi Shirkolaei, H. R. Dalili Oskouei, M. Abbasi
This paper presents an array antenna 1*4 on the human thigh. This antenna can also be installed depending on the radius of any part of the body such as the human arm and waist. Given the actual size of these organs, an antenna must be designed that does not overlap with its side element. Therefore, the used antenna dimension for the array should be minimized at f = 2.45 GHz (ISM operation frequency). As known, the antenna gain decreases with the reduction of the dimensions. To compensate for this decrease, an antenna must be designed that produces maximum gain under normal conditions (Rogers RT/duroid 5880 substrate with a relative permittivity of 2.2). One way to get high-gain antennas is to use multilayer patches (the reason for high-gain antennas being justified because of the reflection of the wave between the patches and ground plane in several steps). For increase gain, a stacked patch antenna fed through a coaxial line is used. Other advantages of this antenna include easy fabrication, low cost, and low cross-polarization due to the type of antenna feed. Also, due to the coupling between two patches, the bandwidth of the antenna is greater than conventional antennas. Due to the need for more bandwidth in these antennas it is justified that if there is little precision in the fabrication, a good return loss can be achieved at f = 2.45 GHz.