# US 9,002,297 B2 · Mobile device and tunable antenna therein > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,002,297 B2 - Document ID: US9002297B2 - Status: Granted - Kind: B2 - Application number: 13/670,068 - Filed: 2012-11-06 - Published: 2014-05-08 - Granted: 2015-04-07 - Earliest claimed: 2012-11-06 - Assignees: HTC Corporation - Applicants: HTC Corporation - Inventors: Ju-Hung Chen; Chien-Pin Chiu; Chang-Yen Cheng; Chi-Hsien Chiu - Web page: https://patentgrep.com/patent/US9002297B2 ## CPC - H04B 1/18: Input circuits, e.g. for coupling to an antenna or a transmission line (coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H) - H04B: TRANSMISSION ## Abstract A mobile device includes an antenna, an ESD (Electrostatic Discharge) protection component, a plurality of branches, and a switch. The antenna is configured to transmit and receive an RF (Radio Frequency) signal. The branches provide different inductances or different capacitances, and are respectively coupled to a ground voltage terminal. The switch is coupled through the ESD protection component to the antenna, and switches between the branches according to a control signal such that the antenna is capable of operating in a plurality of frequency intervals. The ESD protection component is configured to protect the switch from being damaged. ## Claims ### Claim 1 A mobile device, comprising: an antenna, transmitting and receiving an RF (Radio Frequency) signal; an ESD (Electrostatic discharge) protection component; a plurality of branches, providing different inductances or capacitances, and respectively coupled to a ground voltage terminal; and a switch, coupled through the ESD protection component to the antenna, and switching between the branches according to a control signal such that the antenna is capable of operating in a plurality of frequency intervals, wherein the ESD protection component is configured to protect the switch from being damaged, wherein the mobile device further comprises: a processor, coupled to the switch and the antenna, and performing a selection procedure to generate the control signal, and wherein the selection procedure comprises the steps of: obtaining, by the antenna, a signal indicator of the RF signal; determining, by the processor, whether the signal indicator is greater than or equal to a first threshold value; if not, performing a scan procedure to cause the antenna to operate in all of the frequency intervals one after another; during the scan procedure, monitoring, by the processor, the signal indicator to search for a maximum value of the signal indicator; and controlling the antenna to operate in a target frequency interval corresponding to the maximum value of the signal indicator. ### Claim 2 (depends on 1) The mobile device as claimed in claim 1, wherein the ESD protection component comprises an ESD protection capacitor, and the ESD protection capacitor is coupled between the antenna and the switch to block a DC (Direct Current) signal. ### Claim 3 (depends on 2) The mobile device as claimed in claim 2, wherein a capacitance of the ESD protection capacitor is approximately from 1 pF to 100 pF. ### Claim 4 (depends on 1) The mobile device as claimed in claim 1, wherein the ESD protection component comprises an ESD protection inductor, and the ESD protection inductor is coupled between the antenna and the ground voltage terminal to guide an ESD current to the ground voltage terminal. ### Claim 5 (depends on 4) The mobile device as claimed in claim 4, wherein the ESD protection inductor is disposed away from the switch and the branches. ### Claim 6 (depends on 4) The mobile device as claimed in claim 4, wherein an inductance of the ESD protection inductor is approximately from 1 nH to 100 nH. ### Claim 7 (depends on 1) The mobile device as claimed in claim 1, wherein the branches comprise a plurality of inductors or a plurality of capacitors. ### Claim 8 (depends on 1) The mobile device as claimed in claim 1, wherein the antenna is a monopole antenna, a loop antenna, a slot antenna, or a PIFA (Planar Inverted F Antenna). ### Claim 9 (depends on 1) The mobile device as claimed in claim 1, further comprising: a feeding element, coupled to a signal source, and configured to excite the antenna. ### Claim 10 (depends on 9) The mobile device as claimed in claim 9, wherein the feeding element is directly coupled to the antenna. ### Claim 11 (depends on 9) The mobile device as claimed in claim 9, wherein a coupling gap is formed between the feeding element and the antenna. ### Claim 12 (depends on 9) The mobile device as claimed in claim 9, further comprising: a PCB (Printed Circuit Board), wherein the feeding element is a conductive trace disposed on the PCB. ### Claim 13 (depends on 1) The mobile device as claimed in claim 1, wherein when the RF signal received by the antenna is in a DTV (Digital Television) band, and the frequency intervals are approximately from 170 MHz to 810 MHz. ### Claim 14 (depends on 1) The mobile device as claimed in claim 1, further comprising: a controller, selectively coupled to one of a plurality of signal sources to excite the antenna such that the antenna is capable of operating in a DTV (Digital Television) band, a GPS (Global Positioning System) band, a Div (Diversity) band, a Bluetooth band, a Wi-Fi band, and/or a WLAN (Wireless Local Area Network) band. ### Claim 15 (depends on 1) The mobile device as claimed in claim 1, wherein the scan procedure is performed from the highest frequency interval to the lowest frequency interval. ### Claim 16 (depends on 1) The mobile device as claimed in claim 1, wherein the selection procedure further comprises: obtaining, by the processor, a packet lost number of the RF signal; and determining, by the processor, whether the packet lost number is greater than a second threshold value, wherein the scan procedure is performed only if the signal indicator is smaller than the first threshold value and the packet lost number is greater than the second threshold value. ### Claim 17 A mobile device, comprising: an antenna, transmitting and receiving an RF (Radio Frequency) signal; an ESD (Electrostatic discharge) protection component; a plurality of branches, providing different inductances or capacitances, and respectively coupled to a ground voltage terminal; and a switch, coupled through the ESD protection component to the antenna, and switching between the branches according to a control signal such that the antenna is capable of operating in a plurality of frequency intervals, wherein the ESD protection component is configured to protect the switch from being damaged, wherein the mobile device further comprises: a processor, coupled to the switch and the antenna, and performing a selection procedure to generate the control signal, and wherein the selection procedure comprises the steps of: obtaining, by the antenna, a signal indicator of the RF signal; determining, by the processor, whether the signal indicator is greater than a first threshold value; if not, performing a scan procedure to cause the antenna to operate in at least a portion of the frequency intervals one after another; during the scan procedure, monitoring, by the processor, the signal indicator to search for an allowable value of the signal indicator, wherein the allowable value is greater than the first threshold value; and controlling the antenna to operate in a target frequency interval corresponding to the allowable value of the signal indicator. ### Claim 18 (depends on 17) The mobile device as claimed in claim 17, wherein the scan procedure is performed from the highest frequency interval to the lowest frequency interval. ### Claim 19 (depends on 17) The mobile device as claimed in claim 17, wherein the scan procedure is performed from a middle frequency interval to the highest frequency interval, and then from the middle frequency interval to the lowest frequency interval. ### Claim 20 (depends on 17) The mobile device as claimed in claim 17, wherein the selection procedure further comprises: obtaining, by the processor, a packet lost number of the RF signal; and determining, by the processor, whether the packet lost number is greater than a second threshold value, wherein the scan procedure is performed only if the signal indicator is smaller than the first threshold value and the packet lost number is greater than the second threshold value.