Radio frequency switch circuit
A radio frequency (RF) switch circuit in which an RF switch and a switch controller are formed on a single CMOS substrate and floating resistors are connected to a deep N type well substrate, an N type well substrate, and a P type well substrate to thereby increase linearity with respect to input power. In the RF switch having at least one NMOS (N type Metal Oxide Semiconductor) switch changing a transmission path of an RF signal, an N type terminal formed on a first deep N type well substrate receives driving power through a floating resistor, a P type terminal formed on a first P type substrate receives body power through a floating resistor, and the two N type terminals formed on the first P type substrate receive gate power through a floating resistor, and in the switch controller having at least one NMOS switch and at least one PMOS (P type Metal Oxide Semiconductor) switch controlling changing of a path of the RF switch, an N type terminal formed on a second deep N type well substrate and an N type terminal formed on the first N type substrate receive driving power through floating resistors.
1. A radio frequency (RF), switch circuit comprising:
an RF switch including at least one first N-type metal oxide semiconductor (NMOS) switch configured to change a transmission path of an RF signal; and
a switch controller including at least one second NMOS switch and at least one P-type metal oxide semiconductor (PMOS) switch configured to control the RF switch, wherein
the at least one first NMOS switch includes
a first N-type terminal formed on a first deep N-type well substrate formed on a chip substrate, and
a first P-type terminal and two second N-type terminals formed on a first P-type substrate formed on the first deep N-type well substrate, wherein the first N-type terminal is configured to receive a driving power through a first floating resistor, the first P-type terminal is configured to receive a body power through a second floating resistor, and the two second N-type terminals are configured to receive a gate power through a third floating resistor,
the at least one second NMOS switch includes
a third N-type terminal formed on a second deep N-type well substrate formed on the chip substrate, and
a second P-type terminal and two fourth N-type terminals formed on a second P-type substrate formed on the second deep N-type well substrate,
the at least one PMOS switch includes a fifth N-type terminal and two third P-type terminals formed on a first N-type substrate formed on the chip substrate,
the third N-type terminal and the fifth N-type terminal are configured to receive driving powers through a fourth floating resistor and a fifth floating resistor, respectively,
the switch controller comprises:
an oscillator configured to provide a reference signal;
a charge pump configured to convert a voltage level of the reference signal from the oscillator;
a decoder configured to decode a control bit from an external source; and
a level shifter configured to shift the voltage level converted by the charge pump according to the decoded control bit from the decoder and to provide level-shifted voltage to the RF switch, and
each of the oscillator, the charge pump, the decoder, and the level shifter includes the at least one second NMOS switch and the at least one PMOS switch.
2. The RF switch circuit of claim 1 , wherein the at least one first NMOS switch includes an N-channel metal oxide semiconductor field effect transistor (MOSFET) formed through a standard PMOS process.
3. The RF switch circuit of claim 1 , wherein the at least one second NMOS switch and the at least one PMOS switch include an N-channel MOSFET and a P-channel MOSFET formed through a standard complementary metal oxide semiconductor (CMOS) process, respectively.