Wireless connections with virtual hysteresis
Circuit connectors for establishing EHF communication include a receiver configured to receive a transmitted EHF electromagnetic signal, and an output circuit coupled to the receiver. The output circuit has two states of operation that correspond to enabling a signal output and disabling the signal output. The output circuit is also configured to change its state of operation responsive to a state of a control signal, and a controller is coupled to the receiver and configured to produce the control signal. The control signal has two states that correspond to a first condition when the received signal exceeds a first threshold and a second condition when the received signal is less than a second threshold.
1. A first contactless connector included in a first device for communicating with a second contactless connector included in a second device using extremely high frequency (EHF) signals, the first contactless connector comprising:
a receiver configured to receive a transmitted EHF electromagnetic signal from the second contactless connector;
a low-pass filter connected to the receiver and configured to generate an averaged signal proportional to a strength of the transmitted EHF signal;
an enable circuit configured to receive the transmitted EHF signal from an output of the low pass filter, the enable circuit configured to output the transmitted EHF signal when a control signal has a first state and configured to not output the transmitted EHF signal when the control signal has a second state; and
a hysteresis logic circuit connected to the low-pass filter and the enable circuit, the hysteresis logic circuit configured to:
produce the control signal having the second state until the determined signal strength of the averaged signal exceeds a first threshold for a first time interval, whereupon the controller produces the control signal having the first state to enable the enable circuit to output the transmitted EHF signal from the receiver; and thereafter
produce the control signal with the second state to disable the enable circuit from outputting the transmitted EHF signal from the receiver when the determined signal strength of the averaged signal fails to meet a second threshold for a second time interval.
2. The first contactless connector of claim 1 , further comprising a demodulator coupled between the receiver and the low pass filter and configured to demodulate the received signal.
3. The first contactless connector of claim 2 , further comprising an amplifier coupled between the low pass filter and the enable circuit, wherein the amplifier compares a demodulated signal from the demodulator with the averaged signal to determine an output signal to provide to the enable circuit.
4. The first contactless connector of claim 1 , wherein the first and second thresholds are the same, and the first and second time intervals are the same.
5. The first contactless connector of claim 1 , wherein the first threshold is greater than the second threshold.
6. The first contactless connector of claim 1 , wherein the hysteresis logic circuit comprises:
a first comparator connected to the low-pass filter and configured to compare the averaged signal with a first reference level corresponding to the first threshold;
a second comparator connected to the low-pass filter and configured to compare the averaged signal with a second reference level corresponding to the second threshold;
a first timer connected to the first comparator configured to determine whether the averaged signal exceeds the first threshold for the first time interval;
a second timer connected to the second comparator configured to determine whether the averaged signal fails to meet the second threshold for the second time interval;
a muting logic circuit connected to the first timer and the second timer, the muting logic circuit configured to determine a state of the control signal based on one or more timer signals received from the first and second timers, the muting logic circuit further configured to produce the control signal with the determined state.
7. The first contactless connector of claim 6 , wherein the muting logic circuit is configured to reset the first timer if the determined signal strength drops below the first signal strength threshold during the first time interval.
8. The first contactless connector of claim 6 , wherein the muting logic circuit is configured to reset the second timer when the first timer reaches the end of the first time interval.
9. The first contactless connector of claim 6 , wherein the muting logic circuit is configured to reset the first timer when the second timer reaches the end of the second time interval.
10. The first contactless connector of claim 1 , wherein the first signal strength threshold and the first time interval are user-selectable.
11. The first contactless connector of claim 1 , wherein the receiver includes an integrated circuit package having an antenna embedded in the package and configured to receive the transmitted EHF electromagnetic signal.
12. A first contactless connector included in a first device for communicating with a second contactless connector included in a second device using extremely high frequency (EHF) signals, the first contactless connector comprising:
a receiver configured to receive a transmitted EHF electromagnetic signal from the second contactless connector;
an output circuit coupled to receive the transmitted EHF signal from an output of the receiver, the output circuit configured to:
output the transmitted EHF signal when a control signal has a first state and configured to not output the transmitted EHF signal when the control signal has a second state; and
a controller coupled to the receiver and configured to:
determine a signal strength of the transmitted EHF signal;
increment a first timer responsive to determining that the determined signal strength is above a first threshold;
produce the control signal having the second state until the first timer reaches a first terminal count, whereupon the controller produces the control signal having the first state to enable the output circuit to output the transmitted EHF signal from the receiver;
increment a second timer responsive to determining that the determined signal strength is below a second threshold; and
produce the control signal with the second state to disable the output circuit from outputting the transmitted EHF signal from the receiver when the second timer reaches a second terminal count.
13. The first contactless connector of claim 12 , wherein the controller is configured to decrement the first timer responsive to determining that the determined signal strength is not above the first threshold.
14. The first contactless connector of claim 12 , wherein the controller is configured to decrement the second timer responsive to determining that the determined signal strength is not below a second threshold.
15. The first contactless connector of claim 12 , wherein the first and second thresholds are the same, and the first and second terminal counts are the same.
16. The first contactless connector of claim 12 , wherein the first threshold is greater than the second threshold.
17. The first contactless connector of claim 12 , wherein the first signal strength threshold and the first terminal count are user-selectable.
18. The first contactless connector of claim 12 , wherein the receiver includes an integrated circuit package having an antenna embedded in the package and configured to receive the transmitted EHF electromagnetic signal.
19. The first contactless connector of claim 12 , wherein producing the control signal having the first state to enable the output circuit to output the transmitted EHF signal from the receiver further comprises resetting the second timer.
20. The first contactless connector of claim 12 , wherein producing the control signal with the second state to disable the output circuit from outputting the transmitted EHF signal from the receiver further comprises resetting the first timer.