Portable data processing device capable of transmitting processed data on a radio by reflection of unmodulated carrier signal externally applied

A portable data processing device, comprising:

• receiving means for receiving an unmodulated carrier signal and a data modulated carrier signal modulated with instruction data via radio transmission;
• data processing means for generating a processed data signal;
• reflecting means for reflecting the unmodulated carrier signal received by said receiving means as a modulated carrier signal, said reflecting means comprising
• variable impedance means coupled to a predetermined reference potential, an impedance of said variable impedance means changing in response to an applied reversed bias voltage,
• impedance conversion means coupled between said receiving means and said variable impedance means, and
• impedance variable means for varying an impedance value of said variable impedance means by applying the reverse bias voltage in response to the processed data signal;
• demodulating means for demodulating the modulated carrier signal received by said receiving means into the instruction data, the instruction data being supplied to said data processing means;
• selective circuit means, coupled to said receiving means, said reflecting means and said demodulating means, for selectively guiding the unmodulated carrier signal and the data modulated carrier signal received by said receiving means to said reflecting means or said demodulating means respectively;
• and
• radiating means, coupled to said reflecting means, for radiating the signal reflected by said reflecting means via radio transmission as the modulated carrier signal.