Abstract: A receiver (30) with an antenna circuit is disclosed, which antenna circuit comprises a coil (31) and either a monopole (35) or a dipole connected to the coil (31). The antenna circuit captures a signal with a wavelength transmitted by a transmitter (1). The coil (31) captures the signal and generates therefrom a current having a frequency corresponding to the wavelength. The coil (31) is dimensioned such that the current is distributed uniformly within the coil (31) at each point in time. Preferably, the monopole (35) or a leg of the dipole has a length corresponding to less than 5% of the wavelength. The invention further relates to a radio transmitter of the same kind. Finally, the invention relates to an RFID tag, a smart card, a mobile device, and a hearing aid, each comprising an inventive receiver (30) and/or an inventive transmitter.

Abstract: Oscillators (10) which oscillate at a fundamental frequency also generate harmonics. The fundamental frequency or a lower harmonic is used for feedback purposes, and a harmonic higher than either the fundamental frequency or the lower harmonic is used for output purposes. As a result, the oscillators (10) operate at a lower frequency than an output frequency and are low cost. Synthesizers (20) coupled to the oscillators (10) also operate at this lower frequency, and modulators (5) comprising such oscillators (10) and synthesizers (20) are low cost. A lower power consumption and less sensitivity to disturbing fields are further advantages. Filtering has become less complicated, and a smaller number of components has resulted in smaller dimensions. The oscillators (10) comprise tuning circuits (11) and amplifiers (12), which amplifiers (12) are fed back via feedback circuits (13). Such an amplifier (12) may comprise just a single transistor (40).

Abstract: A receiver (30) with an antenna circuit is disclosed, which antenna circuit comprises a coil (31) and either a monopole (35) or a dipole connected to the coil (31). The antenna circuit captures a signal with a wavelength transmitted by a transmitter (1). The coil (31) captures the signal and generates therefrom a current having a frequency corresponding to the wavelength. The coil (31) is dimensioned such that the current is distributed uniformly within the coil (31) at each point in time. Preferably, the monopole (35) or a leg of the dipole has a length corresponding to less than 5% of the wavelength. The invention further relates to a radio transmitter of the same kind. Finally, the invention relates to an RFID tag, a smart card, a mobile device, and a hearing aid, each comprising an inventive receiver (30) and/or an inventive transmitter.