| 摘要 |
WIRELESS COMMUNICATION SYSTEM WITH A MODULATION BANDWIDTH COMPARABLE TO OR EXCEEDING THE BANDWIDTH OF THE TRANSMITTER AND/OR RECEIVER ANTENNAS The application relates to a wireless communication system comprising a) a first device comprising a transmitter part comprising a Tx-antenna for transmitting an electrical signal having a signal bandwidth BWsig and b) a second device comprising a receiver part comprising an Rx-antenna for receiving the transmitted electromagnetic signal, at least one of the Tx and Rx- antennas is a narrowband antenna having an antenna bandwidth BWant, wherein the Tx- and/or Rx-antenna bandwidths fulfil the relation BWant = k-BWsig. The application further relates to a transmitter part and a receiver part, to the use of a narrowband antenna and to a method of calibrating a narrowband antenna/tank frequency transfer function of a wireless communication system. The object of the present application is to provide a wireless communication system having a relatively large signal bandwidth with an electrically small antenna. The problem is solved in that the system is adapted to provide that k is smaller than 1.25, and the antenna bandwidth BWant is defined as the -3dB bandwidth of the loaded antenna when it is connected to the communication system, and the signal bandwidth BWsig is defined as the bandwidth within which 99% of the desired signal power is located. Preferably, the system further comprising at least one compensation unit electrically connected to the Tx- or to the Rx-antennas, wherein the compensation unit(s) is/are adapted for compensating for the amplitude and/or phase distortion introduced by the narrowband Tx- and/or Rx-antennas. This has the advantage of providing a wireless communication system suitable for use in relatively small and/or low power devices. The invention may e.g. be used for the handheld communication devices, e.g. listening devices involving wireless communication. FILTE R FIL TER (Tx) HTx s)Hs)(X) HTx(s) i HEx(s) (x 1/H~x(s) 1/HRx(S Tx-part Rx-part FIG. 1a f->f' Tx Rx f'->f Hfr(s) HTx(s) HRx(s) Hf'(s) FILTER FILTER - + x) (Rx) - s 1 )pa_ Rx-part 1/H'Rx(s) BWant FIG. 1b BWig MAG Power density ------------------------- - B [dB] 3dB [dB] --- - -+99% signal power BWsig f fs, fo [Hz] FIG. 1c |
