section 1504 performs both transmission processing of superimposing data on a signal of frequency f 21 and reception processing of acquiring data superimposed on a signal of frequency f 21 furthermore in portable radio apparatus 1500 a sequence hereinafter referred to as u201c seventh sequence u201d made up of antenna 1501 filter 1505 matching circuit 1506 amplifier 1507 and radio section 1508 performs only reception processing of acquiring data superimposed on a signal of frequency f 22 to frequency f 23 furthermore in portable radio apparatus 1500 a sequence hereinafter referred to as u201c eighth sequence u201d made up of antenna 1501 filter 1509 matching circuit 1510 amplifier 1511 and radio section 1512 performs only reception processing of acquiring data superimposed on a signal of frequency f 24 to frequency f 25 hereinafter the components of portable radio apparatus 1500 will be described in detail antenna 1501 functions for example as a mono pole antenna and has an antenna element having an electrical length of u00bc wavelength or less antenna 1501 receives a signal of radio system 21 using frequency f 21 a signal of radio system 22 using frequency f 22 to frequency f 23 and a signal of radio system 23 using frequency f 24 to frequency f 25 and outputs each received signal to filter 1502 filter 1505 and filter 1509 furthermore antenna 1501 transmits a signal of radio system 21 using frequency f 21 inputted from filter 1502 here radio system 22 and radio system 23 have a wider band than radio system 21 filter 1502 is for example a band elimination filter bef which suppresses frequency f 22 to frequency f.