Techniques for specific absorption rate (SAR) sensing elements in SAR circuits
Various embodiments utilize part of an existing antenna pattern in a computing device to implement a specific absorption rate (SAR) sensor element using a radio frequency (RF) filter circuit. The integrated solutions of the present disclosure help to eliminate the external SAR sensor pad requirement and further help to improve wireless performance. The embodiments of the present disclosure may be implemented with a variety of different types of antenna (e.g., slot, metal ring/aperture, PCB, etc.). Other embodiments may be described and claimed.
1. An antenna assembly comprising:
an antenna that includes a first portion and a second portion, the second portion coupled to a radio frequency (RF) port; and
a filter circuit coupled to the antenna, wherein the filter circuit includes:
a low pass filter coupled between the first portion of the antenna and a specific absorption rate (SAR) controller, the low pass filter to filter out an RF signal, and pass an SAR signal from the first and second portions of the antenna to the SAR controller, wherein the RF signal has a higher frequency than the SAR signal; and
a high pass filter coupled between the first portion of the antenna and the second portion of the antenna, the high pass filter to pass the RF signal from the first portion of the antenna to the RF port via the second portion of the antenna, and to filter out the SAR signal.
2. The antenna assembly of claim 1 , wherein the low pass filter includes an inductor coupled between the second portion of the antenna and the SAR controller, and the high pass filter includes a capacitor coupled between the first portion of the antenna and the second portion of the antenna.
3. The antenna assembly of claim 1 , wherein the high pass filter includes a capacitor, and wherein the first antenna portion is coupled to a first lead of the capacitor and the second antenna portion is coupled to a second lead of the capacitor.
4. The antenna assembly of claim 1 , wherein the antenna is an aperture antenna, wherein the first portion of the antenna includes a portion of a chassis, and wherein the second portion of the antenna includes a flexible printed circuit (FPC) antenna pattern.
5. The antenna assembly of claim 1 , wherein the antenna is a printed circuit board (PCB) antenna or a slot antenna.
6. A device comprising:
an antenna that includes a first portion and a second portion;
a radio frequency (RF) port adapted to receive an RF signal from the antenna, the RF port coupled to the second portion of the antenna;
an SAR controller adapted to receive a specific absorption rate (SAR) signal from the antenna; and
a filter circuit coupled to the antenna, wherein the filter circuit includes:
a low pass filter coupled between the first portion of the antenna and the SAR controller, the low pass filter to filter out the RF signal, and pass the SAR signal from the first portion of the antenna to the SAR controller, wherein the RF signal has a higher frequency than the SAR signal; and
a high pass filter coupled between the first portion of the antenna and the second portion of the antenna, the high pass filter to pass the RF signal from the first portion of the antenna to the RF port via the second portion of the antenna, and to filter out the SAR signal.
7. The device of claim 6 , wherein the low pass filter includes an inductor coupled between the first portion of the antenna and the SAR controller, and the high pass filter includes a capacitor coupled between the first portion of the antenna and the second portion of the antenna.
8. The device of claim 6 , wherein the high pass filter includes a capacitor, and wherein the first antenna portion is coupled to a first lead of the capacitor and the second antenna portion is coupled to a second lead of the capacitor.
9. The device of claim 6 , wherein the antenna is an aperture antenna, wherein the first portion of the antenna includes a portion of a chassis, and wherein the second portion of the antenna includes a flexible printed circuit (FPC) antenna pattern.
10. The device of claim 6 , wherein the antenna is a printed circuit board (PCB) antenna or a slot antenna.