# US 2014/0155000 A1 · Capacitive Sensor Device And Radio Transceiver With A Capacitive Sensor Device And A Method For Adjusting A Transmission Power Of A Handheld Radio Transceiver > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0155000 A1 - Document ID: US20140155000A1 - Status: Published application - Kind: A1 - Application number: 14/001,460 - Filed: 2012-02-20 - Published: 2014-06-05 - Earliest claimed: 2011-02-23 - Assignees: Microchip Technology Germany GmbH - Inventors: Holger Erkens - Web page: https://patentgrep.com/patent/US20140155000A1 ## CPC - H04W 52/18: TPC being performed according to specific parameters - H01Q 1/245: {with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure} - H04B 1/3833: {Hand-held transceivers} - H04B 1/3838: {Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use} - H04W 52/288: {taking into account the usage mode, e.g. hands-free, data transmission or telephone} - H04W 52/367: {Power values between minimum and maximum limits, e.g. dynamic range} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - H04B: TRANSMISSION ## Abstract A capacitive sensor device for a handheld radio transceiver for estimating a specific absorption rate (SAR) can be coupled with at least one first electrode, wherein during the operation of the handheld radio transceiver the first electrode is at the same time a sensor electrode of the capacitive sensor device and an antenna of the handheld radio transceiver. Moreover a handheld radio transceiver with such a capacitive sensor device can be provided. Moreover, a method can be provided for adjusting a transmission power of a handheld radio transceiver, wherein an approach of an object to the handheld radio transceiver is detected and wherein depending on the detected approach the transmission power of the handheld radio transceiver is increased or reduced. ## Claims ### Claim 1 Capacitive sensor device for a handheld radio transceiver connected with an antenna element, for estimating a specific absorption rate (SAR) of the handheld radio transceiver, wherein the sensor device is coupled with the antenna element, and wherein during the operation of the handheld radio transceiver the antenna element is at the same time a sensor electrode of the capacitive sensor device and an antenna of the handheld radio transceiver. ### Claim 2 (depends on 1) Capacitive sensor device according to claim 1, wherein the antenna element is coupled via a highpass filter with a transceiver circuit of the handheld radio transceiver, and is coupled via a lowpass filter with the sensor device. ### Claim 3 (depends on 1) Capacitive sensor device according to claim 1, wherein the sensor device further comprises a second electrode, which can be brought into a capacitive coupling with the antenna element, wherein one of the antenna element and the second electrode is operable as transmitting electrode and the respective other one as receiver electrode, and wherein the transmitting electrode can be fed with an electric alternating signal. ### Claim 4 (depends on 1) Capacitive sensor device according to claim 1, wherein the antenna element is operated as a transmitting electrode, and wherein the antenna element receives an electric alternating signal via a lowpass filter. ### Claim 5 (depends on 3) Capacitive sensor device according to claim 3, wherein the sensor device further comprises a third electrode, which is arranged substantially between the antenna element and the second electrode and which is fed with an electric alternating signal which is substantially inverse to the electric alternating signal fed to the transmitting electrode. ### Claim 6 (depends on 2) Capacitive sensor device according to one claim 2, wherein the lowpass filter comprises a microstrip line. ### Claim 7 (depends on 1) Capacitive sensor device according to claim 1, wherein an evaluation circuit of the sensor device is configured to detect an approach of an object to the electrodes of the sensor device and/or a distance of an object from the electrodes of the sensor device. ### Claim 8 (depends on 1) Capacitive sensor device according to claim 1, comprising a detection means for detecting the HF transmission power irradiated at the antenna element, wherein the detected HF transmission power together with the detected approach to the electrodes of the sensor device is included in the estimate of the SAR of the handheld radio transceiver. ### Claim 9 (depends on 1) Handheld radio transceiver, comprising a capacitive sensor device according to claim 1, wherein the antenna element of the handheld radio transceiver is coupled with the capacitive sensor device and in which during the operation of the handheld radio transceiver (10) the antenna element can be operated at the same time as sensor electrode of the capacitive sensor device and as HF antenna of the handheld radio transceiver. ### Claim 10 (depends on 9) Handheld radio transceiver according to claim 9, which is at least one of the group two-way radio, mobile phone, cordless telephone, WLAN device, minicomputer, and tablet PC. ### Claim 11 Method for operating a handheld radio transceiver comprising a capacitive sensor device for a handheld radio transceiver connected with an antenna element, wherein the sensor device is coupled with the antenna element and configured to operate as a sensor electrode of the capacitive sensor device and an antenna of the handheld radio transceiver, the method comprising the steps: using the antenna element of the handheld radio transceiver as a capacitive sensor to determine a capacitive value, estimating a specific absorption rate (SAR) of the handheld radio transceiver from the capacitive value, and increasing or decreasing the transmission power of the handheld radio transceiver depending on the estimate. ### Claim 12 (depends on 11) Method according to claim 11, wherein for detecting the capacitive value, an alternating signal is fed to the antenna element through a low pass filter or transmission line. ### Claim 13 (depends on 11) Method according to claim 11, wherein the HF transmission power irradiated by the antenna is detected and the detected HF transmission power is included in the estimate of the SAR. ### Claim 14 (depends on 11) Method according to claim 11, wherein the capacitive load of the alternating signal is detected as the capacitive value, the capacitive load being a measure for the approach and/or for the distance. ### Claim 15 (depends on 11) Method according to claim 11, wherein a second electrode (EL2) of the capacitive sensor device is brought into a capacitive coupling with the antenna of the handheld radio transceiver, and wherein either the second electrode (EL2) or the antenna element (A/EL1) is operated as a transmitting electrode and the other one as a receiving electrode and wherein the transmitting electrode is fed with an electric alternating signal of the capacitive sensor device, wherein the capacitive coupling between the antenna element (A/EL1) and the second electrode (EL2) is dependent on the proximity of an object and is detected as the capacitive value, and wherein the detected capacitive coupling is a measure for the approach and/or for the distance. ### Claim 16 (depends on 9) Handheld radio transceiver according to claim 9, wherein the antenna element is coupled via a highpass filter with a transceiver circuit of the handheld radio transceiver, and is coupled via a lowpass filter with the sensor device. ### Claim 17 (depends on 9) Handheld radio transceiver according to claim 9, wherein the sensor device further comprises a second electrode, which can be brought into a capacitive coupling with the antenna element, wherein one of the antenna element and the second electrode is operable as transmitting electrode and the respective other one as receiver electrode, and wherein the transmitting electrode can be fed with an electric alternating signal. ### Claim 18 (depends on 9) Handheld radio transceiver according to claim 9, wherein the antenna element is operated as a transmitting electrode, and wherein the antenna element receives an electric alternating signal via a lowpass filter. ### Claim 19 (depends on 18) Handheld radio transceiver according to claim 18, wherein the sensor device further comprises a third electrode, which is arranged substantially between the antenna element and the second electrode and which is fed with an electric alternating signal which is substantially inverse to the electric alternating signal fed to the transmitting electrode. ### Claim 20 (depends on 17) Handheld radio transceiver according to claim 17, wherein the lowpass filter comprises a microstrip line. ### Claim 21 (depends on 9) Handheld radio transceiver according to claim 9, wherein an evaluation circuit of the sensor device is configured to detect an approach of an object to the electrodes of the sensor device and/or a distance of an object from the electrodes of the sensor device. ### Claim 22 (depends on 9) Handheld radio transceiver according to claim 9, comprising a detector for detecting the HF transmission power irradiated at the antenna, wherein the detected HF transmission power together with the detected approach to the electrodes of the sensor device is included in the estimate of the SAR of the handheld radio transceiver.