# US 10,502,777 B2 · Electronic circuit testing method and device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,777 B2 - Document ID: US10502777B2 - Status: Granted - Kind: B2 - Application number: 16/184,859 - Filed: 2018-11-08 - Published: 2019-05-16 - Granted: 2019-12-10 - Earliest claimed: 2017-11-10 - Assignees: STMicroelectronics (Rousset) SAS - Applicants: Stmicroelectronics (Rousset) SAS - Inventors: Yann Bacher; Nicolas Froidevaux - Web page: https://patentgrep.com/patent/US10502777B2 ## CPC - G01R 31/2822: {of microwave or radiofrequency circuits (of attenuation, gain, e.g. using network analyzers G01R27/28)} - G01R 31/002: {where the device under test is an electronic circuit} - H04B 17/10: of transmitters - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H04B: TRANSMISSION ## Abstract A method of testing a first circuit, including: a) applying a first signal between two terminals of the first circuit, the first circuit being powered off; and b) verifying that radio frequency waves transmitted by the first circuit correspond to an expected transmission. ## Claims ### Claim 1 A method, comprising: testing a first circuit, the testing including: applying a first signal between two terminals of the first circuit, the first circuit being powered off; and verifying whether radio frequency waves transmitted by the first circuit correspond to an expected transmission, wherein the verifying comprises: capturing said radio frequency waves simultaneously with applying the first signal; deducing a radio frequency signature of the circuit from the radio frequency waves captured; and verifying whether said radio frequency signature corresponds to a reference signature, wherein the first signal has a plurality of selected frequencies, and wherein, for each selected frequency: the radio frequency signature comprises a respective first value and the reference signature comprises a respective second value; and verifying whether said radio frequency signature corresponds to the reference signature comprises comparing with a threshold a difference in absolute value between the respective first value and the respective second value. ### Claim 2 (depends on 1) The method of claim 1, wherein only the first signal is applied to the first circuit during the testing. ### Claim 3 (depends on 1) The method of claim 1, wherein the first signal varies over time. ### Claim 4 (depends on 1) The method of claim 1, wherein the two terminals are power supply terminals configured to receive a DC voltage or of a power supply voltage. ### Claim 5 (depends on 1) The method of claim 1, wherein the first circuit is an integrated circuit comprising a chip in a package. ### Claim 6 (depends on 1) The method of claim 1, wherein the first signal comprises at least one edge. ### Claim 7 (depends on 1) The method of claim 1, wherein, for each selected frequency, the respective first value is representative of an intensity obtained by a bandpass filtering centered on the selected frequency during the step of verifying whether said radio frequency signature corresponds to the reference signature. ### Claim 8 (depends on 1) The method of claim 1, wherein the first signal has a frequency variable over time and, for each selected frequency, the respective first value is representative of an intensity of the first signal at a time when the first signal is at the selected frequency. ### Claim 9 (depends on 8) The method of claim 8, further comprising, before verifying whether said radio frequency signature corresponds to a reference signature: applying to two terminals of a second circuit a second signal having the selected frequency or plurality of selected frequencies; capturing radio frequency waves transmitted by the second circuit simultaneously with applying the second signal to the two terminals of the second circuit; and deducing the second values from the radio frequency waves transmitted by the second circuit. ### Claim 10 (depends on 8) The method of claim 8, further comprising, before verifying whether said radio frequency signature corresponds to a reference signature: applying to a second circuit a second signal having frequencies covering a frequency range; capturing radio frequency waves transmitted by the third circuit simultaneously with applying the second signal to the two terminals of the second circuit; and selecting the selected frequencies among frequencies corresponding to maximum intensity values of the waves captured simultaneously with applying the second signal to the two terminals of the second circuit. ### Claim 11 A test device, comprising: a signal source configured to apply a first signal between two terminals of a circuit, the circuit being powered off; and a radio frequency wave detector configured to verify whether radio frequency waves transmitted by the circuit correspond to an expected transmission, wherein the radio frequency wave detector is configured to: capture said radio frequency waves simultaneously with the signal source applying the first signal; deduce a radio frequency signature of the circuit from the radio frequency waves captured; and verify whether a radio frequency signature corresponds to a reference signature, wherein the first signal has a plurality of selected frequencies, and wherein, for each selected frequency: the radio frequency signature comprises a respective first value and the reference signature comprises a respective second value; and the radio frequency wave detector is configured to verify whether the radio frequency signature corresponds to the reference signature comprises by comparing with a threshold a difference in absolute value between the respective first value and the respective second value. ### Claim 12 (depends on 11) The device of claim 11, comprising: two contact elements connected to the signal source and configured to be in electric contact with said two terminals of the circuit, wherein the radio frequency wave detector includes: an antenna arranged to capture said radio frequency waves transmitted by the circuit; and a processing circuit connected to the antenna and configured to verify whether said radio frequency waves transmitted by the circuit correspond to the expected transmission. ### Claim 13 (depends on 12) The device of claim 12, comprising an integrated circuit support comprising the two contact elements. ### Claim 14 (depends on 11) The device of claim 11, wherein the first signal has a selected frequency or a plurality of selected frequencies and the processing circuit comprises, for each selected frequency, a bandpass filtering element according to the selected frequency, the filtering element being connected to the antenna. ### Claim 15 (depends on 11) The device of claim 11, wherein, for each selected frequency, the respective first value is representative of an intensity obtained by a bandpass filtering centered on the selected frequency during the step of verifying whether said radio frequency signature corresponds to the reference signature. ### Claim 16 (depends on 11) The device of claim 11, wherein the first signal has a frequency variable over time and, for each selected frequency, the respective first value is representative of an intensity of the first signal at a time when the first signal is at the selected frequency. ### Claim 17 A method, comprising testing a first circuit, the testing including: applying a first signal to a first circuit while the first circuit is off; and verifying whether radio frequency waves transmitted by the first circuit, in response to applying the first signal, correspond to an expected transmission, wherein: the verifying comprises: capturing said radio frequency waves in response to applying the first signal, deducing a radio frequency signature of the circuit from the radio frequency waves captured, and verifying whether said radio frequency signature corresponds to a reference signature; the first signal has a plurality of selected frequencies; and for each selected frequency: the radio frequency signature comprises a respective first value and the reference signature comprises a respective second value; and verifying whether said radio frequency signature corresponds to the reference signature comprises comparing with a threshold a difference in absolute value between the respective first value and the respective second value. ### Claim 18 (depends on 17) The method of claim 17, further comprising, before applying the first signal to the first circuit: applying to a second circuit, corresponding to the first circuit, a second signal having a plurality of selected frequencies; capturing radio frequency waves transmitted by the second circuit in response to applying the second signal to the second circuit; and deducing the second values from the radio frequency waves transmitted by the second circuit. ### Claim 19 (depends on 17) The method of claim 17, wherein, for each selected frequency, the respective first value is representative of an intensity obtained by a bandpass filtering centered on the selected frequency during the step of verifying whether said radio frequency signature corresponds to the reference signature. ### Claim 20 (depends on 17) The method of claim 17, wherein the first signal has a frequency variable over time and, for each selected frequency, the respective first value is representative of an intensity of the first signal at a time when the first signal is at the selected frequency.