Backscatter communication systems, interrogators, methods of communicating in a backscatter system, and backscatter communication methods

A method of communicating in a backscatter system comprising:

• transmitting a forward link communication;
• transmitting a wireless continuous wave signal;
• receiving the forward link communication;
• modulating the wireless continuous wave signal responsive to the receiving the forward link communication, the modulating providing a modulated continuous wave signal having a carrier component and a side band component;
• receiving the modulated continuous wave signal;
• reducing the amplitude of the carrier component of the modulated continuous wave signal while substantially maintaining the amplitude of the side band component;
• and
• outputting the modulated continuous wave signal having the carrier component after the reducing.

A backscatter communications method comprising:

• transmitting a forward link communication and a wireless continuous wave signal using an interrogator;
• receiving the forward link communication using a remote communication device;
• communicating a return link communication comprising a modulated continuous wave signal responsive to the receiving the forward link communication, the communicating including modulating the wireless continuous wave signal using the remote communication device;
• receiving the modulated continuous wave signal using the interrogator;
• reducing the amplitude of the modulated continuous wave signal at a frequency of a carrier component of the modulated continuous wave signal while substantially maintaining the amplitude of the modulated continuous wave signal at other frequencies using the interrogator;
• and
• outputting the modulated continuous wave signal having the reduced amplitude at the frequency of the carrier component.

A coherent backscatter communication method comprising:

• transmitting a wireless forward link communication;
• transmitting a continuous wave signal;
• providing the continuous wave signal as a local signal;
• receiving the wireless forward link communication;
• communicating a wireless return link communication having a carrier component and a side band component, the communicating including modulating the continuous wave signal following the receiving;
• receiving the wireless return link communication;
• reducing the amplitude of the carrier component of the wireless return link communication using the local signal while substantially maintaining the amplitude of the side band component;
• and
• outputting the wireless return link communication having the carrier component having the reduced amplitude and the side band component having the substantially maintained amplitude.

A method of communicating within a coherent backscatter communication system, the method comprising:

• outputting a forward link communication;
• outputting a wireless continuous wave signal;
• providing a local continuous wave signal;
• communicating a modulated continuous wave signal responsive to the outputting the forward link communication;
• receiving the modulated continuous wave signal;
• and
• reducing the amplitude of the modulated continuous wave signal including:
• matching the amplitude of the local continuous wave signal with the amplitude of the received modulated continuous wave signal;
• adjusting the phase of the local continuous wave signal following the matching providing an adjusted continuous wave signal;
• and
• summing the adjusted continuous wave signal with the modulated continuous wave signal.

A method of reducing power within a modulated return link continuous wave signal of a coherent backscatter communication system including an interrogator and a remote communication device, the method comprising:

• transmitting a radio frequency forward link communication;
• transmitting a radio frequency continuous wave signal having a first frequency;
• providing a local continuous wave signal having the first frequency;
• receiving the radio frequency forward link communication;
• modulating the radio frequency continuous wave signal following the receiving the radio frequency forward link communication, the modulating comprising reflecting the radio frequency continuous wave signal using a modulation signal having a second frequency and providing a modulated continuous wave signal having a carrier component and plural side band components;
• receiving the modulated continuous wave signal;
• and
• reducing the amplitude of the carrier component of the modulated continuous wave signal including:
• matching the amplitude of the local continuous wave signal with the amplitude of the modulated continuous wave signal;
• adjusting the phase of the local continuous wave signal following the matching;
• and
• summing the local continuous wave signal and the modulated continuous wave signal following the adjusting.

A method of communicating in a backscatter system comprising:

• transmitting a forward link communication;
• transmitting a wireless continuous wave signal;
• providing a local continuous wave signal;
• receiving the forward link communication;
• modulating the wireless continuous wave signal responsive to the receiving the forward link communication, the modulating providing a modulated continuous wave signal;
• receiving the modulated continuous wave signal;
• and
• reducing the amplitude of the modulated continuous wave signal including:
• matching the amplitude of the local continuous wave signal with the amplitude of the modulated continuous wave signal;
• adjusting the phase of the local continuous wave signal following the matching;
• and
• summing the local continuous wave signal and the modulated continuous wave signal following the adjusting.