Radio frequency coupler apparatus suitable for use in a multi-band wireless communication device

A wireless communication device for operating in multiple radio frequency (RF) bands, the wireless communication device comprising:

• an antenna;
• a receiver coupled to the antenna;
• and
• a transmitter coupled to the antenna, the transmitter comprising:
• a first power amplifier for amplifying RF signals for transmission in a first band of the multiple frequency bands, the first power amplifier having an output;
• a second power amplifier for amplifying RF signals for transmission in a second band of the multiple frequency bands, the second power amplifier having an output;
• a termination device;
• a first coupler coupled to the output of the first power amplifier, the first coupler coupled in series with the termination device;
• a second coupler coupled to the output of the second power amplifier, the second coupler coupled in series with the first coupler;
• and
• a power detector coupled in series with the second coupler.

A wireless telephone for operating in multiple radio frequency (RF) frequency bands, the wireless telephone comprising:

• an antenna;
• a receiver coupled to the antenna;
• and
• a transmitter coupled to the antenna, the transmitter comprising:
• a plurality of RF power amplifiers comprising a RF power amplifier for each RF frequency band within which the wireless telephone transmits;
• a RF coupler apparatus comprising a plurality of couplers and a termination device, each of the plurality of couplers coupled to corresponding ones of the plurality of power amplifiers, each of the plurality of couplers having a though-path coupling element and a coupled-path coupling element, the coupled-path coupling element of all of the plurality of couplers joined in series to form a coupler chain, the termination device coupled in series to one end of the coupler chain;
• and
• a RF power detector coupled to the RF coupler apparatus, the RF power detector comprising a detection diode, the detection diode coupled in series to the other end of the coupler chain.