Abstract: A new design of field programmable gate array (FPGA) direct radio orthogonal modulation wireless transmitter is presented, which overcomes the complex structure of the traditional orthogonal modulation scheme by dropping the digital-to-analogy converter (DAC) and mixer which are necessary between the base-band digital signal processor and radio frequency section in the traditional orthogonal modulation method, making the base-band digital signal processor directly connecting to the radio orthogonal modulator. The new software realizes and digitalizes the traditional wireless transmitter as far as possible. Tests of the wireless transmitting system that is fabricated according to the new design show the bit error ratio (BER) of the new design reaches the BER level of the traditional orthogonal modulation scheme. But the new design need no DAC or mixer that are necessary in the tradition method, which simplifies the system and lowers the cost.