Multi-gigabit per second frequency-shift keying (FSK) transceiver

A 4 frequency-shift keying (4FSK) transmitter, comprising:

• a voltage-controlled oscillator (VCO);
• two data links coupled to the VCO for delivering two parallel streams of input data bits to the VCO;
• and
• an antenna for radiating a multi-frequency modulated signal wireless toward a 4FSK receiver;
• wherein, for each pair of parallel input data bits received from the two data links, the VCO outputs a modulated signal having one of four operating frequencies via four frequency-shift keying (4FSK) modulation, thereby producing the multi-frequency modulated signal, and
• wherein the transmitter further comprises a frequency doubler following the VCO and wherein the frequency doubler is configured to double the four operating frequencies generated by the VCO and frequency tuning ranges of the VCO, thereby generating four target frequencies of the 4FSK modulation.

A 4 frequency-shift keying (4FSK) transmitter, comprising:

• a voltage-controlled oscillator (VCO);
• two data links coupled to the VCO for delivering two parallel streams of input data bits to the VCO;
• and
• an antenna for radiating a multi-frequency modulated signal wireless toward a 4FSK receiver;
• wherein, for each pair of parallel input data bits received from the two data links, the VCO outputs a modulated signal having one of four operating frequencies via four frequency-shift keying (4FSK) modulation, thereby producing the multi-frequency modulated signal,
• the VCO includes two sets of varactors;
• each set of varactors is controlled by one of the two streams of input data bits;
• and
• a voltage applied to each set of varactors is controlled by each stream of the two streams of input data bits, and
• wherein:
• the transmitter further comprises two sets of inverters;
• each set of inverters is coupled between one of two streams of input data bits and the corresponding set of varactors;
• and
• each set of inverters is configured to convert each received data bit in the stream of input data bits into either a digital High voltage or a digital Low voltage for controlling the corresponding set of varactors.

A 4 frequency-shift keying (4FSK) receiver, comprising:

• an antenna for receiving a multi-frequency modulated 4FSK signal generated by a 4FSK transmitter and transmitted toward the 4FSK receiver, wherein the multi-frequency modulated 4FSK signal comprises four operating frequencies associated with a 4FSK modulation;
• a power divider for dividing the multi-frequency modulated 4FSK signal into two paths of two binary bit streams;
• a pair of low-noise amplifiers (LNAs) separately coupled to the two paths and configured as a pair of band-pass filters for filtering two different subsets of the four operating frequencies within the two binary bit streams into two filtered binary bit streams;
• and
• in each of the two paths, a power detector for demodulating the pairs of filtered data bits from the two filtered binary bit streams according to power measurements of the two filtered binary bit streams.