Novel transmitter applied to LTE MTC electric power Internet of Things

Abstract

The invention discloses a novel transmitter applied to an LTE MTC electric power Internet of Things. The novel transmitter comprises: a DSM modulator used for respectively sampling and modulating twopaths of I and Q orthogonal digital baseband signals outputted by a baseband portion to obtain two paths of digital electric signals; a local oscillator variable gain attenuator used for attenuating local oscillator signal power and outputting multiple paths of orthogonal differential signals; an upper mixer used for converting the two paths of digital electric signals and using the same as control signals of a transistor switch in the upper mixer so as to control the transistor switch to select a certain path of the orthogonal differential signals output by the local oscillator variable gainattenuator to obtain and output a radio frequency signal; a variable gain radio frequency amplifier used for amplifying the radio frequency signal at a desired gain; a radio frequency power amplifierused for amplifying the power of the radio frequency signal; and a radio frequency SAW filter used for filtering the out-of-band noise from the radio frequency signal with amplified power. The noveltransmitter disclosed by the invention has low power consumption, can adopt a radio frequency power amplifier with high nonlinearity, and improves the energy efficiency of the transmitter.

Description

technical field [0001] The invention relates to a novel transmitter applied to the LTE MTC power Internet of Things, and belongs to the technical field of radio frequency communication circuits. Background technique [0002] MTC has the characteristics of large coverage, large connection, and high real-time performance. It is a communication technology in the field of Internet of Things. MTC signals are compatible with LTE signals. In theory, LTE transmitters can be used in MTC systems. However, the communication field of the Internet of Things has extremely strong requirements for transceivers with low power consumption. Therefore, the institute needs to develop RF transceiver chips specially for MTC systems. [0003] Legacy transmitters use a baseband DAC and legacy RF transmitter architecture. LTE and MTC systems adopt multi-carrier-based technology, which makes the dynamic range of the transmitter baseband signal larger, so the bit width of the baseband DAC reaches more...

AI Technical Summary

Problems solved by technology

Due to the adoption of multi-carrier-based technology in LTE and MTC systems, the dynamic range of the baseband signal of the transmitter is relatively large, so the bit width of the baseband DAC reaches more than 12 bits, and the baseband DAC will consume more power in the transmitter link

Also because of the large dynamic range of the signal, the required power amplifier must have extremely high linearity, which in turn leads to the low efficiency of the power amplifier

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