High power integrated RF amplifier
View Patent ↗An integrated HF-amplifier has an input bond pad, cells displaced in a first direction, and an output bond pad. Each has a amplifier with input pad, active area, and output pad. The active area is arranged in-between the input and output pads, and the input pad, active area, and output pad are respectively displaced in a second direction substantially perpendicular to the first direction. A first network interconnects input pads of adjacent cells, and extends in the first direction. A second network interconnects output pads of adjacent cells, and extends in the first direction. The first and second networks obtain an output signal at the output bond pad having for all interconnected cells an equal phase shift and amplitude for a same input signal at the input bond pad. At particular bias and phase shift conditions this provides a Doherty amplifier with improved efficiency at power back off.
1. An integrated HF-amplifier structure comprises:
in a first direction in the order mentioned: an input bond pad, a plurality of cells being displaced with respect to each other in the first direction, and an output bond pad, each one of the cells comprises an amplifier having an input pad, an active area, and an output pad, the active area being arranged in-between the input pad and the output pad, and wherein the input pad, the active area, and the output pad are displaced with respect to each other in a second direction substantially perpendicular to the first direction,
a first network comprising first interconnecting means for interconnecting input pads of adjacent ones of the plurality of cells, and extending in the first direction, and
a second network comprising second interconnecting means for interconnecting output pads of adjacent ones of the plurality of cells, and extending in the first direction,
wherein the first network and the second network are constructed for obtaining an output signal at the output bond pad having for all the interconnected cells an equal phase shift and amplitude for a same input signal at the input bond pad.
2. An integrated amplifier structure as claimed in claim 1 , wherein the first interconnecting means comprises a first bond wire extending in the first direction, and the second interconnecting means comprises a second bond wire also extending in the first direction.
3. An integrated amplifier structure as claimed in claim 2 , wherein the first bond wire forms a first inductance, and wherein the second bond wire forms a second inductance.
4. An integrated amplifier structure as claimed in claim 1 , wherein each one of the amplifier cells is arranged on a separate die.
5. An integrated amplifier structure as claimed in claim 1 , wherein an impedance of the first network and the second network is selected to obtain impedance matching.
6. An integrated amplifier structure as claimed in claim 2 , wherein the first on wire directly interconnects input pads of the adjacent amplifier cells.
7. An integrated amplifier structure as claimed in claim 2 , wherein the second bond wire directly interconnects output pads of the adjacent amplifier cells.
8. An integrated amplifier structure as claimed in claim 2 , wherein the first network further comprises a capacitor arranged in series with the first bond wire, the series arrangement being arranged between the input pads, and wherein the input signal is supplied to one of the input pads.
9. An integrated amplifier structure as claimed in claim 2 , wherein the first network further comprises a capacitor arranged in series with the first bond wire, the series arrangement being arranged between the input pads, the capacitor being arranged for supplying the input signal via the capacitor to the input pads.
10. An integrated amplifier structure as claimed in claim 6 , further comprising a first and a second series arrangement of an inductor and an DC-decoupling capacitor connected to each one of the input pads, respectively.
11. An integrated amplifier structure as claimed in claim 6 , further comprising a third and a fourth series arrangement of an inductor and an DC-decoupling capacitor connected to each one of the output pads, respectively.
12. An integrated amplifier structure as claimed in claim 6 , where inductors are made of bond wires or are integrated.
13. An integrated amplifier structure as claimed in claim 1 , wherein at each position in the first direction, the cell is replaced by a row of amplifier cells to obtain in the order mentioned in the second direction: a row of input bond pads, a plurality of rows of cells being displaced with respect to each other in the first direction, and a row of output bond pads, wherein all the rows are arranged in parallel with each other.
14. An integrated circuit comprising an integrated amplifier structure as claimed in claim 1 .
15. An integrated circuit as claimed in claim 14 , wherein the plurality of cells comprises a first cell and a second cell, and wherein the first network and the second network are constructed for obtaining a phase shift of +90° or −90° at a particular operational frequency, and wherein the amplifier of the second cell is arranged for operating in class B or C, thereby providing a Doherty Amplifier.