Radio frequency transmitter having improved receive band rejection function
A radio frequency transmitter includes a transmit circuit configured to generate a transmit signal; a receive band rejection filter comprising a capacitor and an inductor resonating with each other to reject a receive frequency band from the transmit signal, wherein a ratio value of a capacitance value of the capacitor to an inductance value of the inductor is within a predetermined range; and a power amplifying circuit configured to amplify the transmit signal through the receive band rejection filter.
1. A radio frequency transmitter, comprising:
a transmit circuit configured to generate a transmit signal;
a receive band rejection filter comprising a capacitor and an inductor resonating with each other to reject a receive frequency band from the transmit signal, wherein a ratio value of a capacitance value of the capacitor to an inductance value of the inductor is within a predetermined range; and
a power amplifying circuit configured to amplify the transmit signal through the receive band rejection filter.
2. The radio frequency transmitter of claim 1 , wherein the capacitor and the inductor resonate in series with each other, and
in a series resonance circuit in which the capacitance value of the capacitor is C picofarads (pF) and the inductance value of the inductor is C*M1 nanohenry (nH), M1, corresponding to a first ratio value, is within a range of 1 to 20.
3. The radio frequency transmitter of claim 2 , wherein the inductor comprises an inductance element.
4. The radio frequency transmitter of claim 1 , wherein the capacitor and the inductor resonate in parallel with each other, and
in a parallel resonance circuit in which the inductance value of the inductor is L nanohenry (nH) and the capacitance value of the capacitor is L*M2 picofarads (pF), M2, corresponding to a second ratio value, is within a range of 1 to 20.
5. The radio frequency transmitter of claim 4 , wherein the inductor comprises a bonding wire.
6. The radio frequency transmitter of claim 1 , wherein the predetermined range is 1 to 20.
7. A radio frequency transmitter, comprising:
a transmit circuit configured to generate a transmit signal;
a receive band rejection filter configured to reject a receive frequency band from the transmit signal; and
a power amplifying circuit configured to amplify the transmit signal through the receive band rejection filter,
wherein one of the transmit circuit and the power amplifying circuit comprises a capacitor for impedance matching,
the receive band rejection filter comprises an inductor that resonates with the capacitor to reject the receive band, and
a ratio value between a capacitance value of the capacitor and an inductance value of the inductor is within a predetermined range.
8. The radio frequency transmitter of claim 7 , wherein the receive band rejection filter comprises the capacitor and the inductor resonating with each other in series to reject the receive band, and
in a series resonance circuit in which the capacitance value of the capacitor is C pF and the inductance value of the inductor is C*M1 nH, M1, corresponding to a first ratio value, is within a range of 1 to 20.
9. The radio frequency transmitter of claim 8 , wherein the inductor comprises an inductance element.
10. The radio frequency transmitter of claim 7 , wherein the receive band rejection filter comprises the capacitor and the inductor resonating with each other in parallel to reject the receive band, and
in a parallel resonance circuit in which the inductance value of the inductor is L nH and the capacitance value of the capacitor is L*M2 pF, M2, corresponding to a second ratio value, is within a range of 1 to 20.
11. The radio frequency transmitter of claim 10 , wherein the inductor comprises a bonding wire.
12. The radio frequency transmitter of claim 7 , wherein the predetermined range is 1 to 20.
13. A radio frequency transmitter, comprising:
a transmit circuit configured to generate a transmit signal;
a receive band rejection filter receiving the transmit signal and configured to filter a receive frequency band from the transmit signal to create a filtered transmit signal, the receive band rejection filter comprising a capacitor and an inductor resonating with each other; and
a power amplifying circuit configured to amplify the filtered transmit signal;
wherein a ratio value of a capacitance value of the capacitor to an inductance value of the inductor is within 1 to 20.
14. The radio frequency transmitter of claim 13 , wherein the capacitor and the inductor resonate in series with each other.
15. The radio frequency transmitter of claim 14 , wherein the inductor is a bonding wire.
16. The radio frequency transmitter of claim 13 , wherein the capacitor and the inductor resonate in parallel with each other.
17. The radio frequency transmitter of claim 16 , wherein the inductor is a bonding wire.