Polarization-Reconfigurable Filtering Antenna System
The 2013 IEEE AP-S Antenna Design Challenge required student teams to build an antenna system with reconfigurable antenna elements that can adapt to different propagation conditions. Other challenge specifications stated that the antenna system should be used to teach how antennas work, and that the system should operate at 2.4 GHz with its own source. This polarization-reconfigurable filtering antenna technology from Singapore's Nanyang Technological University tied for first place in the challenge. Their antenna system adapts to different polarization states electronically, achieving polarization-match with the incoming electromagnetic waves. It also has intrinsic filtering capability. By integrating filtering functions with the antenna, no additional filter circuit is required.
Transcript
00:00:03 the goal of this challenge is to design an antenna system with reconfigurable antenna elements that can adapt to different propagation conditions in order to achieve the best link performance the antenna system should be used to teach how antennas work polarization reconfigurable filtering antenna we are team prf from naon Technological University this is the
00:00:22 polarization reconfigurable filtering antenna when the two pin DS are used to respectively configure the peration segment the polar ation of the micro strap Patcher can be switched between left hand and right hand circular polarization from the animation the current of lhcp is rotating clockwise while the current of ihcp is rotating anticlockwise if both dos are Switched
00:00:47 Off linear polarization is obtained the PF attender also has an intrinsic filtering property to filter the DC current as the radiating patch and the feed line are not connected thus no DC block is required furthermore the coupling F structure improves the outof band performance therefore we do not need any filter by adjusting the dimensions of
00:01:12 the use slot the return return losss and the accural band weights can be turned to overlap finally the PF attenders are realized on low cost IFR for streets at the front end we have three reconfigurable antennas the angle between the adjacent two antennas can be manually adjusted next next a server motor controls the elevation
00:01:34 anchor the dials on the antennas are connected to a biasing circuit the antennas are connected via a switch to a power detector which then converts the receiv RF power into DC voltage my deck then samples the voltage as digital signals for further processing in addition my deck also controls the polation state antennas and elevation anle using a computer to test
00:01:59 the system we also require a transmitter a voltage control oscillator is used to generate the signal which is then passed to a switch the switch is connected to a rectangular patch Anna and a dual fat CP Square patch antenna the sense of polarization is determined by the exitation port all of the ERS are fabricated in our La using a wiing machine and measure
00:02:25 in the anacronic chamber [Music] lesson one system verification in this lesson we will verify the antenna system and also demonstrate characteristics of various polarization for line of sight propagation antenna 2 is a line of sight with the transmitter now we set the polarization of the transmitter to
00:02:56 linear next we run the L program and it will scan the various paration and antenna sequentially at the end of the program the best link and the next best link are displayed the best link is antenna to with linear polarization and the result of all states are shown in the chart on the right next we change the polarization of
00:03:22 the transmitter from linear to CP and repeat the process for all antennas we record the results and analyze them as follows underline of side propagation for a transmitter of lhcp as expected the best Ling is also lhcp the next B Ling is linearization which is about 3db LS as half of the component is not received the worst link is rhcp the cross polarization as the sense of
00:03:44 rotation is opposite lesson two wallof cans in this lesson we will demonstrate the polarization characteristic of EM wave support reflection now we stack a wall of can to function as a reflective wall and we transmit lhcp from the results the polarization of the B link and the next B link is rhcp the sense of rotation is reversed upon reflection lesson three box in this
00:04:12 lesson we will use a box to demonstrate several propagation conditions first we place an empty box in the middle of the table the result is almost the same as before in lesson one this indicates that the box has little effect on EM waves next we place Metal Sheets on the box interestingly the best link is not antenna 2 but with rhcp finally we place pens by the sight
00:04:37 of the box and the reive power is not higher than before Lesson Four Massy environment in this lesson we will demonst the antenna systems capability to determine the best Link in a messy environment students are asked to randomly Place items that are commoning found in the classroom this is the nonline offsite condition even under such a messy and creditable environment
00:05:01 the antenna system is able to determine the best link and adapt to it next using the same messy environment will increase the height of the transmitter another program is developed to scan the elevation plane the results shows that the best link is antenna to with lhcp at 60° lesson five two rooms now we place a transmitter and antenna
00:05:33 system in two rooms separated by a wall even under such a practical environment the antenna system is able to determine the best link and adapt to it the lesson is over for more details of the antenna system and lessons please refer to the report