Abstract: An amplitude of a carrier signal at an output of an impedance matching block is measured as a first amplitude value. A value of the signal amplitude at the output of the impedance matching block is calculated as a second amplitude value that a signal resulting from amplitude modulation with said modulation factor from said carrier signal should assume, said carrying signal having an amplitude with the first amplitude value. A setting of a transmitter is changed to decrease the carrier signal amplitude at the output of the impedance matching block. An amplitude of a new carrier signal at the output of the impedance matching block is measured as a new amplitude value. The transmitter setting keeps changing so many times until the new amplitude value is equal to or lower than said second amplitude value or within a predetermined tolerance range around said second amplitude value.

Abstract: When communicating with a traditional interrogator of passive smart tags, an actively transmitting smart tag of the invention, even within a data frame being transmitted, observes a first phase (?i) being a phase of a voltage induced in a tag's antenna by an interrogator's high-frequency carrier signal and transmits wave packets in that it excites the antenna with a voltage having a phase (?t), which is always set at the beginning of transmission of each said wave packet shifted with respect to said first phase (?i) by the same phase angle (??). At ??=180° an amplitude of voltage across an interrogator's antenna, when some of said wave packets influence this antenna, attains the largest attainable interference rise. Miniature actively transmitting smart tags are enabled to wirelessly communicate with said traditional interrogator and a communication range of pocket-sized tags is herewith increased.

Abstract: Intermediate digital signals Fi(?), Gi(?), i=1, . . . I, are generated, which result from a comparison of reference potentials of the first input analogue signal at a shifted value of its observed argument and with a suitably reduced amplitude to the potential, which is inverse to said potential, of the third input analogue signal at the same shifted value of the observed argument and with the amplitude reduced in said way, the shifted argument values being uniformly distributed within the first half-period. A value U of the voltage is measured at any value of the observed argument as at that time the highest one of the voltages at terminals with said reference potentials. An actual peak amplitude A of the input analogue signals is determined as A=kI,mU where the factor kI,m is a quotient of the peak amplitude of said input analogue signals and of the mean value of the voltage waveform envelope of the reference potentials pertaining to said peak amplitude.