Modeling Broadband And Circularly Polarized Patch Antennas Using Planar Mo. MIntroduction. In this article, we will model a number of broadband patch antenna designs with both linear and circular polarization characteristics using EM. Cube. We will compare the simulation results with the published measured data. High- Res. The first broadband antenna design to be simulated is a probe- fed, rectangular patch on a thick foam substrate with a cut- out U- slot on it. The permittivity of the foam can be approximate to be equal to 1, i. The following table shows the substrate properties as well as the geometrical dimensions of the U- Slot patch antenna: Table 1: Substrate Properties & Dimensions of U- Slot Patch Antenna on Foam Substrate. Figure 3: Return loss of the U- slot patch antenna, solid line: EM. Picasso results, symbols: measured data presented by Ref. High- Res. Figure 2: Four- port view of the planar structure setup for U- slot patch antenna in EM. Microstrip Antennas antenna-theory.com; Microstrip Antenna Tutorial EM Talk; Microstrip Patch Antenna Calculator; The basics of patch antenna; Design of a Patch Antenna. HI, I am newbie to HFSS and antenna simulation. I have gone through some online tutorials but I have few queries. How to select the substrate thickness and di-electric constant? How to determine the dimensions (L, W. A patch antenna (also known as a rectangular microstrip antenna) is a type of radio antenna with a low profile, which can be mounted on a flat surface. It consists of a flat rectangular sheet or 'patch' of metal, mounted over. Picasso. For the planar Mo. M simulation, a center frequency of 4. GHz and a frequency bandwidth of 4. GHz was assumed, defining the range . Figure 2 shows the planar structure setup in EM. Picasso. Solid line: EM. Picasso results, and symbols: measured data presented by Ref. High- Res. Figure 4: Input impedance of the U- slot patch antenna over the range . Yellow solid line: EM. Picasso results for input resistance, red solid line: EM. This calculator calculates the length and width of a patch antenna based on the frequency. Microstrip Patch Antenna Calculator. Microstrip Patch Antenna Calculator. Microstrip Patch Antenna Calculator. Rectangular Microstrip Patch Antenna with Designer Layers Stackup Analysis and Design of ISM-Band Patch Antenna Array By: John Herrmann. Picasso results for input reactance, yellow symbols: measured input resistance presented by Ref. High- Res. Figure 4 compares the real and imaginary parts of the input impedance of the patch antenna as simulated by EM. Picasso and the measured data presented by Ref. Figure 5 shows the simulated voltage standing wave ratio of the U- slot patch antenna as compared with the measured data given by the same reference. Figures 7 and 8 shows the radiation pattern cuts at the YZ plane (E- Plane) and ZX plane (H- Plane), respectively. Figure 8 shows both co- polarized and cross- polarized components of the far field. Figures 7 and 8 also compare EM. Picasso. Red solid line: Cross- polarized far field component. Red symbols: Cross- polarized far field component. High- Res. Figure 7: 2. D E- plane radiation pattern of the U- slot patch antenna at f = 4. GHz. Solid line: EM. Picasso results, and symbols: measured data presented by Ref. High- Res. Figure 6: Figure 6: 3. D radiation pattern of the U- slot patch antenna computed by EM. Picasso at f = 4. GHz. High- Res. U- Slot Patch Antenna On Dielectric Substrate. The previous U- slot antenna was constructed on a foam substrate resembling a patch floating over an air layer. Next, we consider the same U- slot patch design on a conductor- backed dielectric substrate with . The parameters and dimensions are shown in Figure 1. The following table shows the substrate properties as well as the geometrical dimensions of the U- Slot patch antenna on the dielectric substrate: Table 2: Substrate Properties & Dimensions of U- Slot Patch Antenna on Dielectric Substrate. Figure 1. 0: A comparison of (a) directivity of the U- slot patch antenna on the dielectric substrate as computed by EM. Picasso (solid line), and (b) measured data for the gain of the antenna presented by Ref. High- Res. Figure 9: Voltage standing wave ratio (VSWR) of the U- slot patch antenna on the dielectric substrate over the range . Solid line: EM. Picasso results, and symbols: measured data presented by Ref. It also shows the measured VSWR = 2 bandwidth of the antenna as presented by Ref. This is equivalent to a bandwidth of 0. GHz or 2. 5%. Figure 1. U- slot patch antenna on the dielectric substrate computed by EM. Picasso. It also shows the measure gain data presented by Ref. T The following table shows the substrate properties as well as the geometrical dimensions of the double U- Slot patch antenna: Table 3: Substrate Properties & Dimensions of Double U- Slot Patch Antenna on Foam Substrate. Figure 1. 2: Planar structure setup for double U- slot patch antenna in EM. Picasso. High- Res. Figure 1. 1: Geometry of double U- slot patch antenna on a foam substrate. High- Res. Figure 1. Return loss of the double U- slot patch antenna computed by EM. Picasso over the range . High- Res. Figure 1. Voltage standing wave ratio (VSWR) of the double U- slot patch antenna over the range . Solid line: EM. Picasso results, and symbols: measured data presented by Ref. However, not all geometrical dimensions are clearly specified. For this report, we assumed certain values of the parameters based on the visual inspection of the given drawing. Figure 1. 2 shows the planar structure setup for the double U- slot patch in EM. Picasso. Figure 1. EM. Picasso for this antenna, where one can see an impedance bandwidth of about 4. The following table shows the substrate properties as well as the geometrical dimensions of the L- feed patch antenna: Table 4: Substrate Properties & Dimensions of L- Feed Patch Antenna on Foam Substrate. Figure 1. 6: Planar structure setup for L- feed patch antenna in EM. Picasso. High- Res. Figure 1. 5: Geometry of L- feed patch antenna on a foam substrate. In the fabricated antenna used for measurement, the inner conductor of the coaxial feed is bent at a 9. In EM. Picasso, we modeled the coaxial probe with a vertical PEC via of radius r and height Lv, which is then transitioned to a horizontal PEC strip of length Lh. Figure 1. 6 shows the planar structure setup for the L- feed patch in EM. Picasso. Solid line: EM. Picasso results, and symbols: measured data presented by Ref. High- Res. Figure 1. Input impedance of the L- feed patch antenna over the range . Yellow solid line: EM. Picasso results for input resistance, red solid line: EM. Picasso results for input reactance, yellow symbols: measured input resistance presented by Ref. A VSWR < 2 bandwidth of 3. High- Res. Figure 2. D radiation pattern of the L- feed patch antenna computed by EM. Picasso at f = 4. GHz. Blue solid line: EM. Picasso results for co- polarized far field component, red solid line: EM. Picasso results for cross- polarized far field component, blue symbols: measured data for co- polarized far field component presented by Ref. High- Res. Figure 2. D E- plane radiation pattern of the L- feed patch antenna at f = 4. GHz. Solid line: EM. Picasso results, and symbols: measured data presented by Ref. Figure 2. 2 shows both co- polarized and cross- polarized components of the far field. Figures 2. 1 and 2. EM. Picasso. It also shows the measure gain data presented by Ref. High- Res. Now we turn our attention to circularly polarized (CP) patch antenna designs. The first CP patch to be considered is a probe- fed rectangular patch with two opposite corner truncations as shown in Figure 2. This patch is located on a thin foam substrate, and as a result, it is not expected to provide a large bandwidth. The following table shows the substrate properties as well as the geometrical dimensions of the CP patch antenna: Table 5: Substrate Properties & Dimensions of CP Patch Antenna with Corner Truncations. The yellow symbols shows the measured 1. B points as reported by Ref. High- Res. Figure 2. Planar mesh of the CP patch with corner truncations in EM. Picasso. Figure 2. EM. Picasso for the CP patch antenna with corner truncations. The simulated and measured 1. B impedance bandwidths agree quite well. Solid line: EM. Picasso results, and symbols: measured data presented by Ref. High- Res. Figure 2. D radiation pattern of the CP patch antenna with corner truncations computed by EM. Picasso at f = 5. GHz. A figure of merit for the performance of a circularly polarized antenna is its axial ratio (AR). Figure 2. 8 shows the computed axial ratio of the CP patch antenna with corner truncations over the range . High- Res. The rectangular patch with cut corners is a narrowband antenna. By increasing the foam thickness and cutting out a U- slot from the surface of the patch, one can increase the impedance bandwidth of the antenna as well as its axial ratio bandwidth. Figure 2. 9 shows the geometry of the CP U- slot patch antenna with corner truncations. The following table shows the substrate properties as well as the geometrical dimensions of the CP U- Slot patch antenna: Table 6: Substrate Properties & Dimensions of CP U- Slot Patch Antenna with Corner Truncations on Foam Substrate. High- Res. Figure 3. Planar structure setup for CP U- slot patch antenna in EM. Picasso. Figure 3. EM. Picasso. Solid line: EM. Picasso results, and symbols: measured data presented by Ref. This reference reports a measured impedance bandwidth of 1. EM. Picasso shows a slightly larger bandwidth up to 4. GHz. Solid line: EM. Picasso results, and symbols: measured data presented by Ref. High- Res. Figure 3. D radiation pattern of the CP U- slot patch antenna with corner truncations computed by EM. Picasso at f = 3. GHz. Figure 3. 4 shows the axial ratio of the U- slot patch antenna on the foam substrate computed by EM. Picasso. It also shows the measure axial ratio data presented by Ref. High- Res. Another method of achieving a broadband CP antenna is to use an L- feed in conjunction with a rectangular patch with corner truncations on a thick foam substrate. In this way, one can increase the impedance bandwidth of the antenna as well as its axial ratio bandwidth. Figure 3. 5 shows the geometry of the CP L- feed patch antenna with corner truncations. The following table shows the substrate properties as well as the geometrical dimensions of the CP L- feed patch antenna: Table 7: Substrate Properties & Dimensions of CP L- feed Patch Antenna with Corner Truncations on Foam Substrate. High- Res. Figure 3. Planar structure setup for CP L- feed patch antenna in EM. Picasso. Figure 3. EM. Picasso. Solid line: EM. Picasso results, and symbols: measured data presented by Ref. This reference reports a measured impedance bandwidth of 3. Solid line: EM. Picasso results, and symbols: measured data presented by Ref. High- Res. Figure 3.
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