Dis-engaging test point
A test point circuit includes a main RF signal path (e.g., transmission line, lumped-element network, etc.), a test point RF signal circuit, a test point structure having a center conductor and corresponding grounded sleeve and being configured for connecting to a test probe for monitoring the RF signal carried through the main RF signal path, and a switch between the main RF signal path and the test point RF signal circuit. In the open position of the switch, the signal in the main RF signal path is prevented from propagating to the center conductor of the test point structure. In the closed position of the switch, the RF signal can propagate from the main RF signal path to the center conductor of the test point structure. The test probe mated to the test point structure can then measure or monitor the RF signal carried through the main RF signal path.
1. A test point circuit comprising:
a main RF signal path,
a test point structure having a center conductor and a grounded sleeve and being configured for connecting to a test probe for monitoring an RF signal carried through the main RF signal path,
a test point RF signal circuit connecting the main RF signal path to the test point structure, the test point RF signal circuit comprising a switch,
wherein, in an open position of the switch, the signal in the main RF signal path is prevented from propagating through the test point RF signal circuit and to the test point structure, and, in a closed position of the switch, the RF signal can propagate from the main RF signal path to the test point RF signal circuit and the test point structure such that the test probe connected to the test point structure can be used to measure the RF signal.
2. The test point circuit of claim 1 further comprising means for detecting the presence of the test probe when the test probe is mated to the test point structure.
3. The test point circuit of claim 2 further comprising a linkage connecting the detecting means and the switch, the switch being normally open, and wherein the linkage is configured to close the switch when the detecting means detects the presence of the test probe mated to the test point structure, such that when the switch is closed the RF signal propagates from the main RF signal path to the test point RF signal circuit and the test point structure so that the test probe connected to the test point structure can be used to measure the RF signal.
4. The test point circuit of claim 2 , wherein the detecting means comprises a conductive resilient spring mounted to extend into an interior of the grounded sleeve of the test point either (i) through an opening of the grounded sleeve surrounding the center conductor, or (ii) from a printed circuit board (PCB) side, wherein the conductive resilient spring is positioned to be contacted by a grounded body of the test probe when the test probe is mated to the test point structure.
5. The test point circuit of claim 4 , wherein the sleeve includes the opening through which the spring is at least partially positioned.
6. The test point circuit of claim 4 , wherein the conductive resilient spring is electrically isolated from the grounded sleeve when the test probe is not mated to the test point structure, and the spring is electrically connected to the grounded sleeve via the grounded body of the test probe when the test probe is mated to the test point structure.
7. The test point circuit of claim 2 , wherein the detecting means comprises a flexible grounding pad that is positioned within an interior of the grounded sleeve of the test point structure, the grounding pad being positioned to be contacted by a grounded body of the probe when the test probe is mated to the test point structure.
8. The test point circuit of claim 7 , wherein the grounding pad is electrically isolated from the grounded sleeve when the test probe is not mated to the test point structure, and the grounding pad is electrically connected to the grounded sleeve via the grounded body of the test probe when the test probe is mated to the test point structure.
9. The test point circuit of claim 1 , wherein the test point circuit forms part of broadband and hybrid fiber coax (HFC) equipment.
10. A test point circuit comprising:
a main RF signal path,
a test point structure having a center conductor and a grounded sleeve, the test point structure being configured for connecting to a test probe for monitoring an RF signal carried through the main RF signal path,
a test point RF signal circuit connecting the main RF signal path to the test point structure, the test point RF signal circuit comprising a switch,
wherein, in an open position of the switch, the RF signal in the main RF signal path is prevented from propagating through the test point RF signal circuit and to the test point structure, and, in a closed position of the switch, the RF signal can propagate from the main RF signal path to the test point RF signal circuit and the test point structure such that the test probe connected to the test point structure can be used to measure the RF signal,
a means for detecting the presence of the test probe when the test probe is mated to the test point structure, and
a linkage connected between the detecting means and the switch, wherein the linkage is configured to close the switch when the detecting means detects the presence of the test probe when the test probe is mated to the test point structure.
11. The test point circuit of claim 10 , wherein the detecting means comprises a resilient spring mounted at least partially within the grounded sleeve of the test point surrounding the center conductor, and wherein the spring is positioned to be contacted by the test probe when the test probe is mated to the test point structure.
12. The test point circuit of claim 11 , wherein the grounded sleeve includes an opening in which the spring is at least partially positioned.
13. The test point circuit of claim 11 , wherein the spring is electrically isolated from the center conductor.
14. The test point circuit of claim 10 , wherein the detecting means comprises a grounding pad that is positioned within the grounded sleeve of the test point surrounding the center conductor, the grounding pad being positioned to be contacted by the test probe when the test probe is mated to the test point structure.
15. The test point circuit of claim 10 , wherein the detecting means is coupled to ground when the test probe is mated to the test point structure.
16. The test point circuit of claim 10 , wherein the detecting means is not coupled to ground when the test probe is not mated to the test point structure.
17. The test point circuit of claim 10 , wherein the test point circuit forms part of broadband and hybrid fiber coax (HFC) equipment.
18. A method of monitoring an RF signal carried through a main RF signal path using a test point circuit that is connected to the main RF signal path, said method comprising:
detecting the presence of a test probe mated to a test point structure; and
changing the state of a switch in the test point circuit, which electrically connects the main RF signal path to a center conductor of the test point structure, from an open state to a closed state, thereby directing the RF signal from the main RF signal path through the test point circuit and to the center conductor of the test point structure.
19. The method of claim 18 further comprising the step of returning the switch back to the open state when the presence of the test probe is no longer detected.
20. The method of claim 18 , wherein the detecting step comprises detecting when a flexible conductive spring mounted to the test point structure is contacted by a surface of a grounded body of the test probe.
21. The method of claim 18 , wherein the detecting step comprises detecting when a flexible grounding pad mounted to the test point structure is contacted by a surface of a grounded body of the test probe.