3. You are asked to build an anechoic chamber for testing how well the 100 MHz FM antenna in a new car works, as shown in Fig. 1 below (anechoic chamber is a room that can ideally eliminate most of the reflection of the EM waves when the EM wave hits the walls of the room, therefore very useful for various antennas and wireless devices testing as it can shield external EMI and also properly characterize the antenna gain without various reflections in the room, etc). Consider a slab made of a commercial RF absorber material (RAM) of 1 m thickness sitting on top of a perfectly conducting metal square plate, as many of these RAM-coated metal square plates are mounted on the walls of the anechoic chamber to reduce the EM reflection (like tiles covering the entire wall). In this case, if a 100-MHz uniform plane wave is normally incident from the air side at the air-absorber-metal interface. For this RAM, use r = 6.93 i 8.29 and ur =1 at 100 MHz. Find the percentage of incident power lost in the absorber material. Hint: this is a 3-medium problem where the 3rd medium is a perfect conductor, where n3 =0 (25 pts) Please comment on if this RAM works well or not for building this anechoic chamber. (5 pts) 3. You are asked to build an anechoic chamber for testing how well the 100 MHz FM antenna in a new car works, as shown in Fig. 1 below (anechoic chamber is a room that can ideally eliminate most of the reflection of the EM waves when the EM wave hits the walls of the room, therefore very useful for various antennas and wireless devices testing as it can shield external EMI and also properly characterize the antenna gain without various reflections in the room, etc). Consider a slab made of a commercial RF absorber material (RAM) of 1 m thickness sitting on top of a perfectly conducting metal square plate, as many of these RAM-coated metal square plates are mounted on the walls of the anechoic chamber to reduce the EM reflection (like tiles covering the entire wall). In this case, if a 100-MHz uniform plane wave is normally incident from the air side at the air-absorber-metal interface. For this RAM, use r = 6.93 i 8.29 and ur =1 at 100 MHz. Find the percentage of incident power lost in the absorber material. Hint: this is a 3-medium problem where the 3rd medium is a perfect conductor, where n3 =0 (25 pts) Please comment on if this RAM works well or not for building this anechoic chamber. (5 pts)
