Current-mode transmitter structure

Abstract

This invention relates to a transmitter structure, is particularly applicable to a higher frequency, specifically relates to a current-mode transmitter structure, and belongs to the technical field of radio frequency integrated circuit. The current-mode transmitter provided in the technical scheme of the invention comprises a phase-locked loop circuit generated by a local oscillator signal, a voltage-to-current switching circuit, an E-type current-mode power amplifier, a power combiner and a transmitting antenna. The voltage-to-current switching circuit switches a baseband voltage signal into a current signal so as to control the E-type current-mode power amplifier; then, the local oscillator signal is directly used as an input signal to drive the E-type current-mode power amplifier to improve the efficiency of the power amplifier; the power combiner transforms a differential signal into a single-ended signal, and the single-ended signal is transmitted by the antenna. The current-mode transmitter structure provided in the invention has a simple and compact structure, reduces the complexity of the circuit, effectively improves the efficiency and linearity of the transmitter, and completely satisfies the efficiency and linearity requirements of the radio transmitter system.

Description

technical field [0001] The invention relates to a transmitter (Transmitter) structure, specifically a current-mode transmitter structure (Current-mode Transmitter), which belongs to the technical field of radio frequency integrated circuits. Background technique [0002] The present invention can be applied in a wide range of fields, especially in applications with relatively high frequencies. The traditional transmission chain structure block diagram is as follows: figure 1 As shown, it is mainly composed of the following parts: a fractional frequency synthesizer PLL including a voltage-controlled oscillator VCO, an up-mixer MIXER1 for generating a carrier frequency, a mixer MIXER2 for signal modulation, a power amplifier PA and a transmitting antenna. In the design of the transmitter, in order to avoid the frequency pulling effect, usually the voltage controlled oscillator will not oscillate at the carrier frequency. For the application of lower RF frequency, it can oscill...

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Problems solved by technology

[0003] The structure of the traditional transmitter is relatively complicated, and the link is very long, especially for higher radio frequency, the link is too long, it is easy to cause the problem of large signal loss, too small transmission power, and too low efficiency

In the design of RF chips, the device that occupies the main area is usually an inductor, which generally occupies nearly 50% or more of the area of ​​the RF chip. Reducing the number of inductors and the area of ​​the inductor in the RF chip is usually used to reduce the chip area and reduce the size of the chip. cost-effective manner, and such as figure 1 In the traditional transmitter structure shown, there are inductors in PLL, MIXER1, MIXER2 and PA, and the four inductors occupy almost most of the chip area

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