Method of communications in a backscatter system, interrogator, and backscatter communications system

A backscatter system interrogator comprising:

• an antenna configured to receive a backscatter signal;
• a quadrature downconverter coupled to the antenna and configured to convert the backscatter signal to produce I and Q signals;
• a combiner coupled directly to the downconverter and configured to combine the I and Q signals to produce a combined signal;
• and
• automatic gain control circuitry coupled to the combiner and configured to amplify the combined signal.

A backscatter system interrogator comprising:

• an antenna configured to receive a backscatter signal;
• a quadrature downconverter coupled to the antenna and configured to convert the backscatter signal to produce I and Q signals;
• a combiner coupled directly to the downconverter and configured to combine the I and Q signals to produce a combined signal;
• and
• an amplifier coupled to the combiner and configured to amplify the combined signal to produce an amplified signal, and a voltage controlled amplifier coupled to the first mentioned amplifier and configured to further amplify the amplified signal.

A backscatter system interrogator comprising:

• an antenna configured to receive a backscatter signal;
• an IQ downconverter coupled to the antenna and configured to produce I and Q signals;
• a combiner coupled directly to the IQ downconverter and configured to combine the I and Q signals to produce a combined signal;
• and
• an analog to digital converter configured to convert the combined signal to a digital signal.

A method of communications in a backscatter system, the method comprising:

• receiving a backscatter signal;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals to produce a combined signal;
• converting the combined signal to a digital signal;
• and
• amplifying the combined signal prior to converting to a digital signal.

A method of communications in a backscatter system the method comprising:

• receiving a backscatter signal;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals to produce a combined signal;
• converting the combined signal to a digital signal;
• and
• amplifying the combined signal with a voltage controlled amplifier prior to converting to a digital signal.

A method of communications in a backscatter system, the method comprising:

• receiving a backscatter signal;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals immediately after the downconverting to produce a combined signal;
• and
• performing automatic gain control on the combined signal.

A method of communications in a backscatter system, the method comprising:

• receiving a backscatter signal;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals immediately after the downconverting to produce a combined signal;
• and
• amplifying after the I and Q signals are combined to produce an amplified signal, and then further amplifying the amplified signal with a voltage controlled amplifier.

A method of communications in a backscatter system, the method comprising:

• receiving a backscatter signal;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals immediately after the downconverting to produce a combined signal;
• and
• converting the combined signal to a digital signal.

A method of communications in a backscatter system including an interrogator and a wireless communications device having an integrated circuit having a processor, and a memory, a receiver, and a backscatter modulator coupled to the processor, the method comprising:

• transmitting a command to the wireless communications device from the interrogator;
• transmitting a continuous wave to the wireless communications device from the interrogator for modulation by the backscatter modulator, after the transmitting;
• receiving with the interrogator a modulated backscatter signal from the wireless communications device;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• as combining the I and Q signals after the downconverting to produce a combined signal;
• and
• converting the combined signal to a digital signal.

A method of communications in a backscatter system including an interrogator and including a wireless communications device having an integrated circuit having a processor, and a memory, a receiver, and a backscatter modulator coupled to the processor, the method comprising:

• transmitting a command to the wireless communications device from the interrogator;
• transmitting a continuous wave to the wireless communications device from the interrogator for modulation by the backscatter modulator, after the transmitting;
• receiving with the interrogator a modulated backscatter signal from the wireless communications device;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals immediately after the downconverting to produce a combined signal;
• and
• converting the combined signal to digital signal.

A method of communications in a backscatter system including an interrogator and including a wireless communications device having an integrated circuit having a processor, and a memory, a receiver, and a backscatter modulator coupled to the processor, the method comprising:

• transmitting a command to the wireless communications device from the interrogator;
• transmitting a continuous wave to the wireless communications device from the interrogator for modulation by the backscatter modulator, after the transmitting;
• receiving with the interrogator a modulated backscatter signal from the wireless communications device;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals immediately after the downconverting to produce a combined signal;
• and
• performing automatic gain control on the combined signal to produce an amplified signal, and converting the amplified signal to a digital signal.

A method of communications in a backscatter system including an interrogator and including a wireless communications device having an integrated circuit having a processor, and a memory, a receiver, and a backscatter modulator coupled to the processor, the method comprising:

• transmitting a command to the wireless communications device from the interrogator;
• transmitting a continuous wave to the wireless communications device from the interrogator for modulation by the backscatter modulator, after the transmitting;
• receiving with the interrogator a modulated backscatter signal from the wireless communications device;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals immediately after the downconverting to produce a combined signal, the combining of the I and Q signals including using an analog quadrature combiner;
• and
• converting the combined signal to a digital signal.

A method of communications in a backscatter system including an interrogator and including a wireless communications device having an integrated circuit having a processor, and a memory, a receiver, and a backscatter modulator coupled to the processor, the method comprising:

• transmitting a command to the wireless communications device from the interrogator;
• transmitting a continuous wave to the wireless communications device from the interrogator for modulation by the backscatter modulator, after the transmitting;
• receiving with the interrogator a modulated backscatter signal from the wireless communications device;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals immediately after the downconverting to produce a combined signal;
• and
• amplifying, after the I and Q signals are combined, to produce an amplified signal, and converting the amplified signal to a digital signal.

A method of communications in a backscatter system including an interrogator and including a wireless communications device having an integrated circuit having a processor, and a memory a receiver, and a backscatter modulator coupled to the processor the method comprising:

• transmitting a command to the wireless communications device from the interrogator;
• transmitting a continuous wave to the wireless communications device from the interrogator for modulation by the backscatter modulator, after the transmitting;
• receiving with the interrogator a modulated backscatter signal from the wireless communications device;
• downconverting the backscatter signal with an IQ downconverter to produce I and Q signals;
• combining the I and Q signals immediately after the downconverting to produce a combined signal;
• and
• amplifying, after the I and Q signals are combined, to produce an amplified signal, further amplifying the amplified signal with a voltage controlled amplifier to produce a twice amplified signal, and converting the twice amplified signal to a digital signal.