Test system with adjustable radio-frequency probe array
Electronic device structures may be tested using a radio-frequency test system. The radio-frequency test system may include radio-frequency test equipment and an associated test fixture. The radio-frequency test equipment may be used in generating and measuring radio-frequency signals. The test fixture may contain adjustable structures that allow the positions of radio-frequency test probes to be adjusted. The test system may be configured to position radio-frequency probes in the test fixture so that some probe contacts form electrical connections with conductive antenna structures. The radio-frequency probes may contain other contacts that are positioned to form electrical connections with conductive electronic device housing structures. During radio-frequency testing, the test equipment in the test system may apply radio-frequency test signals to the device structures under test using the test probes. Corresponding radio-frequency test signals may be measured by the test equipment.
1. A method of testing electronic device structures that have a plurality of antenna resonating elements and an antenna ground structure, comprising:
coupling a plurality of radio-frequency probes to the electronic device structures so that each probe has a first probe conductor directly connected to a respective one of the antenna resonating elements and each probe has a second probe conductor directly connected to the antenna ground structure; and
with test equipment coupled to the radio-frequency probes, performing radio-frequency tests on the electronic device structures using the radio-frequency probes.
2. The method defined in claim 1 wherein performing the radio-frequency tests comprises:
applying radio-frequency signals to the electronic device structures through the radio-frequency probes from the test equipment and receiving radio-frequency signals at the test equipment from the electronic device structures through the radio-frequency probes.
3. The method defined in claim 1 wherein performing the radio-frequency tests comprises identifying faults associated with insufficient electrical coupling between the resonating elements and the ground structures.
4. The method defined in claim 1 wherein the antenna resonating elements and the antenna ground structure form at least one antenna and wherein performing the radio-frequency tests comprises identifying faults in the at least one antenna.
5. The method defined in claim 1 wherein coupling the plurality of radio-frequency probes to the electronic device structure comprises positioning the radio-frequency probes using adjustable probe positioning structures.
6. The method defined in claim 5 wherein positioning the radio-frequency probes comprises adjusting positions of the radio-frequency probes in first, second, and third orthogonal dimensions in three dimensional space.
7. The method defined in claim 1 wherein performing the radio-frequency tests further comprises:
with the test equipment, comparing radio-frequency signal data gathered using the probes to reference data.
8. The method defined in claim 1 wherein performing the radio-frequency tests comprises obtaining forward transfer coefficient data using a pair of the probes.
9. The method defined in claim 1 wherein performing the radio-frequency tests comprises obtaining complex impedance data using at least one of the probes.
10. The method defined in claim 1 further comprising:
clamping the electronic device structures to a test stage while performing the radio-frequency tests.
11. The method defined in claim 1 wherein clamping the electronic device structures to the test stage comprises using a clamp and opposing horizontal and vertical locking blocks to hold the electronic device structures.
12. The method defined in claim 11 further comprising:
supporting the test stage on a sliding mechanism; and
with an additional clamp, clamping the test stage against at least one motion limiting structure.
13. A method of testing electronic device structures that have a plurality of antenna resonating elements and an antenna ground structure, comprising:
coupling a plurality of radio-frequency probes to the electronic device structures so that each probe has a first probe conductor coupled to a respective one of the antenna resonating elements and each probe has a second probe conductor coupled to the antenna ground structure, wherein coupling the plurality of radio-frequency probes to the electronic device structures comprises capacitively coupling the radio-frequency probes to the electronic device structures; and
with test equipment coupled to the radio-frequency probes, performing radio-frequency tests on the electronic device structures using the radio-frequency probes.
14. A method of identifying an optimal set of testing locations for radio-frequency probes to couple to an electronic device structure that has a plurality of antenna resonating elements that are coupled to an antenna ground structure, comprising:
with adjustable probe positioning structures, positioning the radio-frequency probes at a plurality of different potential testing locations so that each probe is coupled to a respective one of the antenna resonating elements and the antenna ground structure;
with test equipment coupled to the radio-frequency probes, transmitting radio-frequency test signals and measuring responses to the radio-frequency test signals while the radio-frequency probes are located at each of the plurality of different potential testing locations; and
based on the measured responses, identifying an optimal set of testing locations for the radio-frequency probes to couple to the electronic device structure.
15. The method defined in claim 14 wherein adjusting the positions of the radio-frequency probes comprises adjusting the positions of the radio-frequency probes along first, second, and third orthogonal axes in three dimensional space.
16. The method defined in claim 14 further comprising:
with the test equipment, calculating input reflection coefficients based on the measured responses to the radio-frequency test signals.