Radio frequency front-end circuit of wireless communication device

A radio frequency (RF) front-end circuit of a wireless communication device, comprising:

• an up-converter, configured to up-convert a transmitted signal according to a local oscillation (LO) signal to generate an up-converted transmitted signal;
• a transmitting amplifier, coupled to the up-converter, configured to amplify the up-converted transmitted signal to generate an amplified transmitted signal;
• and
• an output driver, coupled to the transmitting amplifier, configured to output a driving transmitted signal according to the amplified transmitted signal;
• wherein at least one of the up-converter and the transmitting amplifier comprises a transformer load, and the transformer load comprises a switchable inductor;
• when the wireless communication device is set to operate in a first mode, the LO signal is set to have a first frequency, and the switchable inductor is set to have a first inductance;
• and when the wireless communication device is set to operate in a second mode, the LO signal is set to have a second frequency, and the switchable inductor is set to have a second inductance;
• the switchable inductor comprises:
• a first negative sub-inductor;
• a first positive sub-inductor;
• a second negative sub-inductor, wherein a first end of the second negative sub-inductor is coupled to the first negative sub-inductor;
• a second positive sub-inductor, wherein a first end of the second positive sub-inductor is coupled to the first positive sub-inductor;
• a first negative switch, coupled between the first end of the second negative sub-inductor and a reference voltage;
• a first positive switch, coupled between the first end of the second positive sub-inductor and the reference voltage;
• a second negative switch, coupled between a second end of the second negative sub-inductor and the reference voltage;
• and
• a second positive switch, coupled between a second end of the second positive sub-inductor and the reference voltage;
• wherein:
• when the wireless communication device is set to operate in the first mode, the first negative switch and the first positive switch are turned off, and the second negative switch and the second positive switch are turned on;
• and
• when the wireless communication device is set to operate in the second mode, the first negative switch and the first positive switch are turned on, and the second negative switch and the second positive switch are turned off.

A radio frequency (RF) front-end circuit of a wireless communication device, comprising:

• a receiving amplifier, configured to amplify a RF received signal to generate an amplified received signal;
• and
• a down-converter, coupled to the receiving amplifier, configured to down-convert the amplified received signal according to a local oscillation (LO) signal to generate a down-converted received signal;
• wherein the receiving amplifier comprises a transformer load, and the transformer load comprises a switchable inductor;
• when the wireless communication device is set to operate in a first mode, the LO signal is set to have a first frequency, and the switchable inductor is set to have a first inductance;
• and when the wireless communication device is set to operate in a second mode, the LO signal is set to have a second frequency, and the switchable inductor is set to have a second inductance;
• the switchable inductor comprises:
• a first negative sub-inductor;
• a first positive sub-inductor;
• a second negative sub-inductor, wherein a first end of the second negative sub-inductor is coupled to the first negative sub-inductor;
• a second positive sub-inductor, wherein a first end of the second positive sub-inductor is coupled to the first positive sub-inductor;
• a first negative switch, coupled between the first end of the second negative sub-inductor and a reference voltage;
• a first positive switch, coupled between the first end of the second positive sub-inductor and the reference voltage;
• a second negative switch, coupled between a second end of the second negative sub-inductor and the reference voltage;
• and
• a second positive switch, coupled between a second end of the second positive sub-inductor and the reference voltage;
• wherein:
• when the wireless communication device is set to operate in the first mode, the first negative switch and the first positive switch are turned off, and the second negative switch and the second positive switch are turned on;
• and
• when the wireless communication device is set to operate in the second mode, the first negative switch and the first positive switch are turned on, and the second negative switch and the second positive switch are turned off.