# US 2021/0281111 A1 · Wireless device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0281111 A1 - Document ID: US20210281111A1 - Status: Published application - Kind: A1 - Application number: 17/191,124 - Filed: 2021-03-03 - Published: 2021-09-09 - Earliest claimed: 2020-03-06 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Yuki Shoji - Web page: https://patentgrep.com/patent/US20210281111A1 ## CPC - H02J 50/12: of the resonant type - H02M 7/219: in a bridge configuration - H02J 50/80: involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices - H02M 1/083: {for the ignition at the zero crossing of the voltage or the current} - H02M 7/5387: in a bridge configuration - H02P 7/04: {by means of a H-bridge circuit} - H02M 3/33592: {having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer} - H03L 7/08: Details of the phase-locked loop - Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - H03L: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES (generation of oscillations H03B) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A wireless device includes a power transmission coil configured to transmit power wirelessly, a power reception coil configured to receive the power wirelessly, a switch circuit configured to apply a voltage to the power transmission coil based on a first switching signal, and a rectification circuit configured to rectify a voltage output from the power reception coil based on a second switching signal and apply the rectified voltage to a load, wherein the switch circuit and the rectification circuit each include a plurality of bidirectional switches. ## Claims ### Claim 1 A wireless device comprising: a power transmission coil configured to transmit power wirelessly; a power reception coil configured to receive the power wirelessly from the power transmission coil; a switch circuit configured to apply a voltage to the power transmission coil based on a first switching signal; and a rectification circuit configured to rectify a voltage output from the power reception coil based on a second switching signal and apply the rectified voltage to a load, wherein the switch circuit and the rectification circuit each include a plurality of bidirectional switches. ### Claim 2 (depends on 1) The wireless device according to claim 1, wherein the first switching signal and the second switching signal have a same period. ### Claim 3 (depends on 1) The wireless device according to claim 1, wherein a dead time is provided to a driving signal of each of the plurality of bidirectional switches to prevent a through current. ### Claim 4 (depends on 1) The wireless device according to claim 1, wherein the switch circuit is a full-bridge, half-bridge, or push-pull switch circuit. ### Claim 5 (depends on 1) The wireless device according to claim 1, wherein the switch circuit performs a zero current switching (ZCS) operation or a zero voltage switching (ZVS) operation. ### Claim 6 (depends on 1) The wireless device according to claim 1, further comprising a resonance circuit between the power reception coil and the rectification circuit. ### Claim 7 (depends on 1) The wireless device according to claim 1, further comprising a resonance circuit between the power transmission coil and the switch circuit. ### Claim 8 (depends on 1) The wireless device according to claim 1, further comprising: a reference frequency source configured to output a reference frequency signal; a first driving circuit configured to output the first switching signal to the switch circuit based on the reference frequency signal; and a second driving circuit configured to output the second switching signal to the rectification circuit based on the reference frequency signal. ### Claim 9 (depends on 8) The wireless device according to claim 8, further comprising a phase shifting circuit configured to phase-shift the reference frequency signal, wherein the second driving circuit outputs the second switching signal to the rectification circuit based on the reference frequency signal that is phase-shifted by the phase shifting circuit. ### Claim 10 (depends on 8) The wireless device according to claim 8, further comprising: a first phase locked loop (first PLL) circuit to which the reference frequency signal is input and that outputs a first signal; and a second phase locked loop (second PLL) circuit to which the reference frequency signal is input and that outputs a second signal, wherein the first driving circuit outputs the first switching signal to the switch circuit based on the first signal, and wherein the second driving circuit outputs the second switching signal to the rectification circuit based on the second signal. ### Claim 11 (depends on 10) The wireless device according to claim 10, further comprising a phase shifting circuit configured to phase-shift the second signal, wherein the second driving circuit outputs the second switching signal to the rectification circuit based on the second signal that is phase-shifted by the phase shifting circuit. ### Claim 12 (depends on 8) The wireless device according to claim 8, wherein the second driving circuit outputs the second switching signal to the rectification circuit based on the reference frequency signal that is transmitted from the reference frequency source via electromagnetic field coupling communication or optical coupling communication. ### Claim 13 (depends on 1) The wireless device according to claim 1, wherein the load is a motor. ### Claim 14 (depends on 13) The wireless device according to claim 13, wherein the power reception coil wirelessly transmits a back electromotive force generated by the motor to the power transmission coil. ### Claim 15 (depends on 1) The wireless device according to claim 1, wherein each bidirectional switch of the switch circuit is driven by the first switching signal based on a potential of a source terminal of the bidirectional switch as a reference, and wherein each bidirectional switch of the rectification circuit is driven by the second switching signal based on a potential of a source terminal of the bidirectional switch as a reference.