摘要:
A transmitter that can reduce noise without using an SAW filter whose IC integration is hard, and copes with two modulation formats of constant envelope modulation and non-constant envelope modulation, and a downsized and low-cost wireless communication apparatus that uses the transmitter are provided. The transmitter includes a quadrature modulator that modulates an input signal by quadrature modulation, a first amplifier that amplifies a modulation signal outputted by the quadrature modulator, and a second amplifier that amplifies an output signal of the first amplifier. The first amplifier operates as a limiter when the modulation format is the constant envelope modulation, and performs linear operation when the modulation format is the non-constant envelope modulation.
摘要:
A transmitter that can reduce noise without using an SAW filter whose IC integration is hard, and copes with two modulation formats of constant envelope modulation and non-constant envelope modulation, and a downsized and low-cost wireless communication apparatus that uses the transmitter are provided. The transmitter includes a quadrature modulator that modulates an input signal by quadrature modulation, a first amplifier that amplifies a modulation signal outputted by the quadrature modulator, and a second amplifier that amplifies an output signal of the first amplifier. The first amplifier operates as a limiter when the modulation format is the constant envelope modulation, and performs linear operation when the modulation format is the non-constant envelope modulation.
摘要:
A communication semiconductor integrated circuit (high frequency IC) that has a function of differentially-singly converts and outputs a transmitted signal suppressing deterioration of a harmonic suppression characteristic and enables miniaturization and an electronic component (high frequency module) that mounts the communication semiconductor integrated circuit are provided. In the communication semiconductor integrated circuit (high frequency IC) having a limiter that amplifies a modulated and up-converted transmitted signal and supplies a power amplifier with the signal, an unbalanced reduction means having, for example, differential MOS transistors is provided in collectors or drains of differential transistors that construct the limiter to output pins and continue to apply a current to the output pins and reduces the impedance of the transistor on an off side even when one of the transistors enters an off state in accordance with an input signal in parallel to the transistor.
摘要:
A communication semiconductor integrated circuit includes a phase control loop and an amplitude control loop. A gain of a variable gain amplifier when it is detected from an output of the comparator that the amplitudes of the reference signal and the feedback signal are equal to each other while a predetermined DC voltage is applied to an amplifier which amplifies an output of a transmission oscillation circuit and is controlled by the amplitude control loop to vary the gain of the variable gain amplifier on a feedback path is held in a register. Thereafter, the DC voltage is changed to another value to detect the gain of the variable gain amplifier, so that the gain of a variable gain amplifier on the forward path is decided on the basis of the detected gain and the gain held in the register.
摘要:
A communication semiconductor integrated circuit includes a phase control loop and an amplitude control loop. A gain of a variable gain amplifier when it is detected from an output of the comparator that the amplitudes of the reference signal and the feedback signal are equal to each other while a predetermined DC voltage is applied to an amplifier which amplifies an output of a transmission oscillation circuit and is controlled by the amplitude control loop to vary the gain of the variable gain amplifier on a feedback path is held in a register. Thereafter, the DC voltage is changed to another value to detect the gain of the variable gain amplifier, so that the gain of a variable gain amplifier on the forward path is decided on the basis of the detected gain and the gain held in the register.
摘要:
A communication semiconductor integrated circuit includes a phase control loop and an amplitude control loop. A gain of a variable gain amplifier when it is detected from an output of the comparator that the amplitudes of the reference signal and the feedback signal are equal to each other while a predetermined DC voltage is applied to an amplifier which amplifies an output of a transmission oscillation circuit and is controlled by the amplitude control loop to vary the gain of the variable gain amplifier on a feedback path is held in a register. Thereafter, the DC voltage is changed to another value to detect the gain of the variable gain amplifier, so that the gain of a variable gain amplifier on the forward path is decided on the basis of the detected gain and the gain held in the register.
摘要:
A transmitter is provided which includes a transmitting circuit that does not require a high-performance low noise VCO restricting cost reduction thereof and that can reduce the number of parts without requiring an RF filter. A direct conversion that does not require a transmission VCO is applied to the transmitting circuit. In order to achieve noise reduction in a receiving band, low-pass filters are provided a IQ input sections of a modulator that converts IQ signals into RF signals. In comparison with a conventional transmitter using offset PLL, an external VCO required in addition to an RF integrated circuit, a power amplifier, and a front end circuit is reduced. Even in current transistor performance, by using a filter having rapid waveform characteristics such as a SAW more inexpensive than the VCO, or the like, it is possible to provide a GSM/GSM 1800/GSM1900 triple band transmitter.
摘要:
A communication semiconductor integrated circuit includes a phase control loop and an amplitude control loop. A gain of a variable gain amplifier when it is detected from an output of the comparator that the amplitudes of the reference signal and the feedback signal are equal to each other while a predetermined DC voltage is applied to an amplifier which amplifies an output of a transmission oscillation circuit and is controlled by the amplitude control loop to vary the gain of the variable gain amplifier on a feedback path is held in a register. Thereafter, the DC voltage is changed to another value to detect the gain of the variable gain amplifier, so that the gain of a variable gain amplifier on the forward path is decided on the basis of the detected gain and the gain held in the register.
摘要:
A transmitter is provided which includes a transmitting circuit that does not require a high-performance low noise VCO restricting cost reduction thereof and that can reduce the number of parts without requiring an RF filter. A direct conversion that does not require a transmission VCO is applied to the transmitting circuit. In order to achieve noise reduction in a receiving band, low-pass filters are provided at IQ input sections of a modulator that converts IQ signals into RF signals. In comparison with a conventional transmitter using offset PLL, an external VCO required in addition to an RF integrated circuit, a power amplifier, and a front end circuit is reduced. Even in current transistor performance, by using a filter having rapid waveform characteristics such as a SAW more inexpensive than the VCO, or the like, it is possible to provide a GSM/GSM 1800/GSM1900 triple band transmitter.
摘要:
Provided is a linerless thermosensitive recording body package, a roll of a linerless thermosensitive recording sheet being packaged in the linerless thermosensitive recording body package, the linerless thermosensitive recording sheet including a support, a thermosensitive color developing layer over one surface of the support, a release layer over the thermosensitive color developing layer, and an adhesive layer over an opposite surface of the support, the linerless thermosensitive recording sheet being wound in roll shape in a manner that the adhesive layer comes to an internal side of the support, wherein a peel force for peeling the linerless thermosensitive recording sheet from the roll is 50 mN/50 mm or greater but 250 mN/50 mm or less, wherein a water content of the linerless thermosensitive recording sheet is 4.5% or higher but 6.5% or lower, the roll of the linerless thermosensitive recording sheet being seal-packaged in the linerless thermosensitive recording body package.