High linearity rf circuit and method for improving linearity thereof

A radio-frequency (RF) circuit comprising:

• an RF path coupled between an RF input port and an RF output port;
• and
• a diode module coupled in shunt to the RF path for circuit linearity improvement, the diode module comprising:
• a capacitor coupled to the RF path;
• a first diode coupled in series to the capacitor at a first node;
• a second diode having one end coupled in series to the first diode at a second node and another end grounded, the second diode and the first diode are reversely cascaded;
• and
• a first connecting bias branch coupled between the first node and ground such that the first connecting bias branch is in parallel to the first diode and the second diode.

A method for improving linearity of a radio-frequency (RF) circuit comprising:

• given an RF path coupled between an RF input port and an RF output port:
• coupling a first diode in shunt to the RF path;
• reversely cascading a second diode to the first diode at a first node;
• coupling a third diode or a capacitor in series between the second diode at a second node and ground;
• coupling a first connecting bias branch between the RF path and the second node such that the first connecting bias branch is in parallel to the first diode and the second diode;
• and
• coupling a second connecting bias branch between the first node and ground such that the second connecting bias branch is in parallel to the second diode and the third diode or the capacitor.