Radio communication transceiver
View Patent ↗A radio communication transceiver achieving impedance matching when the transceiver operates in an output state and an input state respectively in a manner of switching a switch includes a transformer, a switch, a power amplifier (PA), and a low noise amplifier (LNA). The transformer has a primary winding including a first endpoint and a second endpoint and a secondary winding including a first endpoint and a second endpoint. The switch has a gate, a drain, and a source, wherein the gate receives a control signal, the drain is connected to the second endpoint of the primary winding, and the source is connected to the second endpoint of the secondary winding. The PA has an output terminal connected to the first endpoint of the primary winding of the transformer. The LNA has an input terminal connected to the second endpoint of the primary winding of the transformer.
1. A radio communication transceiver, comprising:
a transformer, having a primary winding and a secondary winding, wherein the primary winding has a first endpoint and a second endpoint, and the secondary winding has a first endpoint and a second endpoint;
a switch, having a gate, a drain, and a source, wherein the gate receives a control signal (CS), the drain is connected to the second endpoint of the primary winding of the transformer, and the source is connected to the second endpoint of the secondary winding of the transformer;
a power amplifier (PA), having an output terminal connected to the first endpoint of the primary winding of the transformer; and
a low noise amplifier (LNA), having an input terminal connected to the second endpoint of the primary winding of the transformer;
wherein the switch enables the radio communication transceiver to receive a signal through an antenna and transmit the signal to the LNA corresponding to a first potential of the CS, and enables the signal to be emitted by the antenna through the PA according to a second potential of the CS.
2. The radio communication transceiver according to claim 1 , wherein the switch is turned off corresponding to the first potential of the CS, so that the secondary winding of the transformer is floating.
3. The radio communication transceiver according to claim 1 , wherein the gate of the switch is grounded through a bypass capacitor.
4. The radio communication transceiver according to claim 1 , wherein the LNA comprises an inductor, a first transistor, and a second transistor, a gate of the first transistor is connected to the second endpoint of the primary winding, a source of the first transistor is grounded through the inductor, and a source of the second transistor is connected to a drain of the first transistor.
5. The radio communication transceiver according to claim 4 , wherein the first endpoint of the primary winding of the transformer is connected to the antenna through a coupling capacitor, and the first endpoint of the secondary winding is grounded.
6. The radio communication transceiver according to claim 5 , wherein impedance of the antenna matches with total impedance formed by impedance of the primary winding of the transformer and impedance of the LNA according to the following equation:
Z
out
=
Z
in
*
(
r
)
=
s
(
L
1
+
L
s
)
+
1
sC
gs
+
g
m
L
s
C
gs
wherein Z out is the impedance of the antenna, Z in(r) is the total impedance formed by the primary winding and the LNA, * denotes a conjugated complex, C gs is gate to source parasitic capacitance of the first transistor in the LNA, L s is inductance of the inductor in the LNA, and g−jwrw−2πfifmg m g m is inductance of the first transistor in the LNA.
7. The radio communication transceiver according to claim 1 , wherein an input terminal of the PA is connected to an up-conversion circuit module, and an output terminal of the LNA is connected to a down-conversion circuit module.
8. The radio communication transceiver according to claim 1 , wherein the switch is turned on corresponding to the second potential of the CS, so that the second endpoint of the primary winding of the transformer is electrically coupled to the second endpoint of the secondary winding.
9. The radio communication transceiver according to claim 8 , wherein the primary winding and the secondary winding of the transformer form a radio frequency choker (RFC).
10. The radio communication transceiver according to claim 9 , wherein impedance of the antenna matches with total impedance formed by the primary winding and the secondary winding of the transformer according to the following equation:
Z
in
(
t
)
=
s
×
(
L
1
+
L
2
+
M
12
)
+
1
s
×
C
par
s
=
j
w
k
=
M
12
L
1
×
L
2
wherein Z in (t) is the total impedance formed by the primary winding and the secondary winding of the transformer, L 1 is inductance of the primary winding of the transformer, L 2 is inductance of the secondary winding of the transformer, and M 12 is mutual inductance between the primary winding and the secondary winding of the transformer, and is a coupling coefficient of the primary winding and the secondary winding of the transformer.