Electronics , 10, The proposed antenna is integrated with solar cells and fed by two orthogonal feeding ports to achieve circular polarization. It has a small size of Its main limitations are the narrow bandwidth 2.
Another S-band transparent meshed patch antenna is presented in [10]. They reported a high gain, of 7. Its main limitation, however, is the large antenna size, i. In [11], Ygnacio-Espinoza et al. This is important as it enhances the bandwidth. The proposed antenna operates at 2. To address the bandwidth limitation of patch antennas while maintaining a compact size, several techniques have been proposed, such as introducing slots, with popular shapes being the E- and U-shaped patches [12—15] and using shorting pins or walls [16—18].
In addition, by using thick substrates along with the folded patch feeding technique, the impedance bandwidth of patch antennas can be greatly increased [19]. The authors of [12] proposed an E-shaped patch antenna. The antenna was fed by a folded shaped probe that has unequal arms. They reported a measured impedance bandwidth of The position, the width and the length of the slots was studied to provide an optimal impedance bandwidth of A symmetric U-slotted patch on a The U-slotted patch antenna was printed on FR4 substrate and was placed 8 mm above the ground plane.
A circular microstrip patch loaded with shorting pins operating at X-band can be found in [17]. Finally, the folded patch feeding technique was used in [19], achieving an impedance bandwidth of The E-shaped patch was placed at 20 mm from the ground plane with a shorting wall used to miniaturize the structure while keeping a broad bandwidth.
In this paper, we propose a wideband F-shaped patch antenna for CubeSats communi- cations with an operating frequency of 2. The main idea is to feed the resonance arms of the upper F-shaped patch by a folded patch. This generates two resonant frequen- cies, and hence, achieves a wide bandwidth.
Moreover, three shorting pins between the edges of the upper patch F-shaped patch and the ground plane are used to increase the effective electrical length of the patch and hence reduces its physical size.
They are also used to lower the resonant frequency and widen bandwidth. The proposed antenna is a metal-only antenna with air substrate. This is important as it presents higher efficiency and improved radiation performance due to the absence of high lossy dielectric substrates [20]. The proposed antenna provides a linear polarization and can be used for establishing up- and downlinks with the ground station. Other proposed linear polarized antennas for satellite communications can be found in [21—24].
Lastly, the performance of the proposed antenna is compared with some existing proposed patch antennas for CubeSat in terms of size, bandwidth and gain. Antenna Configuration and Simulation Results 2. Antenna 2. Antenna Structure Structure We selected We selected the the folded folded patch patch feeding feeding approach approach with with air air substrate substrate forfor our our proposed proposed antenna to antenna to broaden broaden its its impedance impedance bandwidth bandwidth [19].
Figure Figure 11 shows shows thethe geometry geometry of of the the proposed metal-only proposed metal-only patch patch antenna antenna for for CubeSat CubeSat communications communications designed designed to to operate operate at at a dominant resonant frequency of 2.
The proposed a dominant resonant frequency of 2. The proposed antenna also incorporates antenna also incorporates shorting pins shorting pins andand aa lower lower folded folded patch patch feed. The The three three shorting shorting pinspins connect connect the the upper upper patch patch with with the the ground ground planeplane in order to in to adjust adjustthe thelower loweroperating operatingfrequency frequency of of 1.
The The diameter diameter of the of shorting the shorting pinspinsthatthat provides provides the the optimal optimal an- antenna bandwidth tenna bandwidth is 3. Moreover, Moreover, the thefolded folded patch patch technique technique is used is used and fed andatfedh2, at to hreduce 2 , to reduce the the coaxial coaxial probe probe length length and and inductance inductance at the at feedthe feed section.
By doingBy doing that, a that, thicker a thicker substrate substrate can be used can which be used which leads to an leads to an improved improved overall impedance overall impedance bandwidth bandwidth [13].
In addition,[13]. The width of theThe the gain of the proposed antenna and ensures zero dielectric losses. Therefore, antenna. Table 1 values. The effect antenna. Figure 1. Proposed Proposed antenna: antenna: a a top top view view and and b b side side view. TableThe 1. Optimal parameters F-shaped patch canofbe theconsidered proposed antenna. This changes W the resonant characteristics of the antenna In otherWwords, 1 this introduces a second RLC resonant Therefore, the antenna can be visualized W3 as two RLC resonant circuits, which,13 when coupled together, can achieve a wider Lbandwidth.
Optimal parameters h1 of the proposed antenna. This changes the resonant characteristics of Therefore, the antennaxcan be visualized as two RLC resonant circuits,0 which, when cou- y Parametric 2.
ParametricAnalysis Analysis Thissection This section outlines aa parametric parametricstudy studythat thataims aims to to identify factors identify thatthat factors affect antenna affect an- performance, i.
HFSS gain. Figure Figure 3 shows 3 shows the simulated the simulated S11 S11 with with width width W varied from Other parameters are fixed. Other parameters are can We fixed. Thisisisbecause This becauseof ofthe theincrease increaseof ofthe thewidth widthof ofthe theradiating radiatingelement. The Thereason reasonthat thatthe the lower resonant frequency is barely affected is because it was generated lower resonant frequency is barely affected is because it was generated by the shorting by the shorting pins.
Therefore, pins. To achieve a wide bandwidth and meetrequired coefficient of the proposed antenna. To achieve a wide bandwidth and meet the the re- resonant quired frequency resonant of 2. The length L2 is varied from 8. We see that the slot length L2 has no effect on the resonant frequency of the proposed antenna. However, S11 improves decreases when increasing the slot length L2.
In addition, when L2 is set to As shown in Figure 5, the width W3 of the lower folded patch influences the bandwidth and the operating frequency. We see that when W3 increases, the operating frequency decreases. For example, when changing W3 is changed from 7 mm to 16 mm, the operating frequency shifts from 2.
Moreover, when W3 is decreased, e. Figure 3. Variation of resonant frequency and reflection coefficient S11 with respect to width W1. We see that when W3 in- creases, the operating frequency decreases. Moreo- ver, when W3 is decreased, e.
Variation 3. Oth parameters are fixed. We see that the slot length L2 has no effect on the resonant frequen of the proposed antenna. However, S11 improves decreases when increasing the sl length L2. GHz 1. As shown in Figure 5, the width W3 of the lower folde patch influences the bandwidth and the operating frequency. We see that when W3 i creases, the operating frequency decreases. For example, when changing W3 is change from 7 mm to 16 mm, the operating frequency shifts from 2.
More ver, when W3 is decreased, e. Figure 4. Variation Variation of ofreflection reflectioncoefficient coefficient S S 11 with respect to the length L2.
Variation of reflection coefficient S11 with respect to the length L2. Figure 5. Variation Figure Variation of of reflection reflectioncoefficient coefficient S11 with S respect 11 with to the respect length to the W3. Variation of reflection coefficient S11 with respect to the length W3. Figure 6 depicts the simulated reflection coefficients of the proposed antenna versus a Figurewith frequency 6 depicts the simulated different values of reflection coefficients L1 e.
We can a frequency with different values of L1 e. We observe that the S11 increases when it has a slight effect on the reflection coefficient S We observe that the S11 increases the L1 increases. For example, increasing L1 from As shown in Figure 7, the variation of L3 has an influence on the reflection coefficient.
When L3 is changed from variation of L3 has an influence on the reflection coefficient. When L3 is changed from This means more power will be reflected back instead of being radiated into being radiated into space.
Figure 6. Variation Variationof ofreflection reflectioncoefficient coefficient S S 11 with respect to the length L1. Figure 7. Variation Variation of of reflection reflectioncoefficient coefficient S S 11 with respect to the length L3.
Shorting Pins Investigation Shorting Pins Investigation In In Figure Figure 8,8, the the effects effectsofofshorting shortingpins pins can can bebe observed observed based based on the on the surface surface current current distribution on the distribution on the top top radiating F-shaped patch. As can be seen from Figure F-shaped patch. As can be seen from Figure 8a, the sur- 8a, the surface current distribution face current dominates distribution dominates around aroundshorting shorting pin 11andandthe thetop top armarm of the of the F-shaped F-shaped patch patchasas well as shorting shortingpin pin2.
The Thecurrent current distribution distribution around around shorting shorting pin pin 3 is also 3 is also moremore pronounced as pronounced as compared comparedtotothe therest restofofthe frequencies the frequencies e. This highlights This thethe highlights effect of the effect three of the shorting three pins pins shorting on the on the first first resonant resonant frequency frequencyofof1.
OnOnthethe other hand, other as depicted hand, in Figure as depicted 8e, 8e, in Figure the surface current is highly concentrated around the middle arm of the F-shaped patch and shorting pin 2, while it weakens around shorting pin 1 and 3.
This indicates that the middle arm has a greater effect on the second resonance of 2. Shorting Pins Investigation In Figure 8, the effects of shorting pins can be observed based on the surface current distribution on the top radiating F-shaped patch.
As can be seen from Figure 8a, the sur- face current distribution dominates around shorting pin 1 and the top arm of the F-shaped Electronics , 10, 50 patch as well as shorting pin 2. The current distribution around shorting pin 3 is also7more of 13 pronounced as compared to the rest of the frequencies e. This highlights the effect of the three shorting pins on the first resonant frequency of 1. On the other hand, as depicted in Figure 8e, the thesurface surfacecurrent currentisishighly highlyconcentrated concentratedaround aroundthe themiddle middlearmarmofofthe theF-shaped F-shapedpatch patch and and shorting pin 2, while it weakens around shorting pin 1 and 3.
This indicatesthat shorting pin 2, while it weakens around shorting pin 1 and 3. This indicates thatthe the middle middle arm arm has hasaagreater greatereffect effecton onthe thesecond secondresonance resonanceofof2. Figure 8. Current distribution on the patch at a 1. Figure 9 shows the simulated S11 with different diameter values of the shorting pins. The diameter D is varied from 2. However, the reflection coefficient S11 improves decreases when D is set to 2. We can also see that the first resonance is shifted from 2 GHz to 1.
The optimal diameter of the shorting pins, which provides a small S11 at 2. Moreover, the effect of the distance d1 between shorting pin 1 and shorting pin 2 and the distance d2 between shorting pin 1 and shorting pin 3 on S11 is shown in Figures 10 and 11, respectively.
It is clearly shown that the distance d1 has a significant effect on the resonant frequency and the matching of the antenna. As the distance d1 varies from In addition, setting d1 to On the other hand, by varying the distance d2 from 5. The main effect observed when changing d2 is on the impedance matching, which improves as the shorting pins 1 and 2 are set to Standalone Panel Antenna - 2.
Technical Specifications. Add to Cart. It is compatible with IEEE Call for Availability. Frequency range MHz - MHz. Integrated spring provides strength at high velocity in vehicles and flexible for overhead Customers Also Viewed.
The wireless broadband omnidirectional antennas are designed to provide maximum performance and reliability under the toughest weather conditions. These antennas feature a UV stable, vented radome S and for International frequency bands.
Versatile and easy to Each cable terminates with an SMA plug male connector Stationary U-Bolt mounting kit for mounting on 1. Antenna J-Pipe with 90 degree swivel mount and 1.
Key Parameters. Electrical Specification. Mechanical Specification. Frequency Bands:. Antenna Properties:. Omni Antenna. Min Frequency MHz :. Max Frequency MHz :. Impedance Ohms :. Max Power Watts :.
0コメント