Abstract: A transmitter in an RFID system, the transmitter includes a signal generator which has a PIN diode and generates a first signal, a directional unit connected to a cathode of the PIN diode; and an antenna connected to the directional unit, wherein the signal generator has a first terminal configured to receive a first control signal to control a frequency band of the first signal and a second terminal configured to receive a second control signal to control a modulation depth of the first signal.

Abstract: An RFID reader comprises a memory having a first data for identifying the reader and a second data associated with the first data stored therein; a communication interface; and a microcontroller unit. The microcontroller unit is configured to transmit the first data via the communication interface; receive a first request for transmitting the second data; transmit the second data via the communication interface; receive a third data via the communication interface; overwrite the second data stored in the memory with third data.

Abstract: A modulator which has a first terminal to receive a carrier signal, a second terminal to receive a first control signal to control a frequency band of the carrier signal and a third terminal to receive a second control signal to control a modulation depth of the carrier signal.

Abstract: A device that comprises at least one image sensor and a processing unit. The at least one image sensor is configured to consecutively capture a plurality of images at a predetermined rate. The processing unit is configured to identify in each of the plurality of images a first region and a second region, wherein intensities of the first region and the second region are different; determine a displacement of the first region from the first image of the plurality of images to the last image of the plurality of images; and output a first signal comprising the displacement.

Abstract: A transmitter in an RFID system, the transmitter includes a signal generator which has a PIN diode and generates a first signal, a directional unit connected to a cathode of the PIN diode; and an antenna connected to the directional unit, wherein the signal generator has a first terminal configured to receive a first control signal to control a frequency band of the first signal and a second terminal configured to receive a second control signal to control a modulation depth of the first signal.

Abstract: An RFID reader comprises a memory having a first data for identifying the reader and a second data associated with the first data stored therein; a communication interface; and a microcontroller unit. The microcontroller unit is configured to transmit the first data via the communication interface; receive a first request for transmitting the second data; transmit the second data via the communication interface; receive a third data via the communication interface; overwrite the second data stored in the memory with third data.

Abstract: A modulator which has a first terminal to receive a carrier signal, a second terminal to receive a first control signal to control a frequency band of the carrier signal and a third terminal to receive a second control signal to control a modulation depth of the carrier signal.

Abstract: A wireless keyboard comprises a plurality of keys, a transmitter, an antenna and a controller. The plurality of keys comprises a set of first type keys and a set of second type keys. Each of the first type keys is associated with one of a plurality of predetermined functions. The controller is configured to receive a first signal from the plurality of keys indicating at least one of the plurality of keys has been selected; determine if the selected at least one of the plurality of keys is one of the first type keys; and activate the transmitter for transmitting a second signal if the selected at least one of the plurality of keys is one of the first type keys, wherein the second signal carries information corresponding to the one of the plurality of predetermined function associated with the selected at least one of the plurality of keys.

Abstract: A wireless short range transmission system comprises a controller, a first oscillator, a transmitter, and an antenna. The transmitter comprises a phase-lock loop frequency synthesizer for receiving a reference signal from the first oscillator and a first modulation signal. The phase-lock loop frequency synthesizer is configured to be turned on by the first modulation signal for generating a carrier signal based on the reference signal. The transmitter further comprises a power amplifier for receiving the carrier signal from the phase-lock loop frequency synthesizer and a second modulation signal. The power amplifier is configured to be turned on/off by the second modulation signal to generate a modulated signal based on the carrier signal. The power amplifier is turned on after the phase-lock loop frequency synthesizer is stabilized and the phase-lock loop frequency synthesizer is turned off with the power amplifier or after the power amplifier has been turned off.

Abstract: A carrier generator for generating a carrier at a frequency of interest in a wireless communications system comprises an oscillator exhibiting a first impedance, the oscillator comprising an energy storage tank configured to generate a periodic signal, the energy storage tank including at least one inductor and at least one capacitor, and an amplifier coupled with the energy storage tank, the amplifier being configured to amplify an amplitude of the periodic signal, an antenna exhibiting a second impedance smaller than the first impedance, and a network coupled between the oscillator and the antenna, the network including at least one inductor or at least one capacitor and being configured to provide a third impedance such that a resultant impedance of the second impedance and the third impedance as viewed from the oscillator toward the antenna is large enough to facilitate the oscillator to generate the carrier at the frequency of interest.

Abstract: A carrier generator for generating a carrier at a frequency of interest in a wireless communications system. The carrier generator comprises a first oscillator configured to generate the carrier. The first oscillator exhibits a first impedance and comprises an energy storage tank, an amplifier, at least one trimming pin and at least one capacitor. The energy storage tank is configured to generate a first periodic signal. The energy storage tank includes at least one inductor and at least one capacitor. The amplifier coupled with the energy storage tank and is configured to amplify an amplitude of the first periodic signal. The at least one trimming pin is configured to adjust the at least one capacitor of the energy storage tank, and the at least one modulation pin is configured to receive a modulation signal. The carrier generator further comprises an antenna exhibiting a second impedance smaller than the first impedance, and a network coupled between the first oscillator and the antenna.

Abstract: A carrier generator for generating a carrier at a frequency of interest in a wireless communications system comprises an oscillator exhibiting a first impedance, the oscillator comprising an energy storage tank configured to generate a periodic signal, the energy storage tank including at least one inductor and at least one capacitor, and an amplifier coupled with the energy storage tank, the amplifier being configured to amplify an amplitude of the periodic signal, an antenna exhibiting a second impedance smaller than the first impedance, and a network coupled between the oscillator and the antenna, the network including at least one inductor or at least one capacitor and being configured to provide a third impedance such that a resultant impedance of the second impedance and the third impedance as viewed from the oscillator toward the antenna is large enough to facilitate the oscillator to generate the carrier at the frequency of interest.

Abstract: An active transmission architecture without battery and the application are proposed, which make use of an analog front-end circuit to convert a received carrier into a dc signal for providing power for the active transmission architecture without battery, and therefore actively produces a replying signal with the same or different frequencies from the carrier. It is not necessary to add an extra power circuit, hence accomplishing the advantage of no battery. The proposed active transmission architecture without battery can apply to RFID systems or be used in applications that require transmitter and receiver modules.