Korea Electronics Technology Institute

Myung-Hyun Yoon

Kwang-Ho Won

Yong Kuk Park

Hae-moon Seo

Seong-Dong Kim

Hae-Moon Seo

Young-Kuk Park

Yeon-Kuk Moon

June-Jae Yoo

The present invention relates to an I/Q modulator using a current-mixing method used for a direct conversion wireless communication transmitter. In accordance with the present invention, an EVM of a wireless communication system, a linearity and a power consumption are improved by converting a D/A converted signal to a current level and then performing a frequency modulation.

I/Q modulator using current-mixing and direct conversion wireless communication transmitter using the same

Disclosed herein is a 2-order sub-harmonic frequency modulator and direct conversion transmitter using the same. The direct conversion transmitter includes a digital modulation unit, a D/A conversion unit, a DC correction and low pass filter unit, a local oscillator, a poly phase signal generation unit, a 2-order sub-harmonic I/Q frequency modulation unit, a power amplification unit, and an antenna. The digital modulation unit digitally modulates a base-band signal and then outputs I and Q component signals. The D/A conversion unit converts the I and Q component signals into analog I and Q component signals. The DC correction and low pass filter unit adjusts DC interfaces of the analog I and Q component signals, passes low frequency components of the analog I and Q component signals and generates I and Q components of a base-band signal. The local oscillator generates a sine wave signal with a frequency of F/2. The poly phase signal generation unit generates a poly phase signal with 2phases. The frequency modulation unit mixes the I and Q components with the poly phase signal with 2phases to generate an output signal with a frequency of F. The power amplification unit amplifies the output of the frequency modulation unit to a required level. The antenna radiates the output signal of the power amplification unit.

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Growing community of inventors

Sungnam, South Korea

Myung-Hyun Yoon