Tunable circuit including integrated filter circuit coupled to variable capacitance, and related integrated circuit (IC) packages and fabrication methods
An exemplary tunable circuit includes an inductor coupled to a node and a first capacitor coupled to the node. The tunable circuit also includes a variable capacitor coupled to the node, such that a total capacitance of the tunable circuit depends on a fixed capacitance of the first capacitor and a variable capacitance of the variable capacitor. In an example, the inductor and the first capacitor are both included in a passive device and the variable capacitor is in a semiconductor device. The variable capacitor allows the total capacitance to be modified for the purpose of, for example, calibrating the capacitance to account for manufacturing variations, and/or adjusting to a frequency range of operation used by wireless devices in a region of the world. The first capacitor may be a higher quality capacitor providing a larger portion of the total capacitance than the variable capacitor.
1. A tunable circuit package, comprising:
a package substrate;
a passive device coupled to the package substrate, the passive device comprising:
an inductor comprising a first terminal and a second terminal, the first terminal coupled to a node; and
a first capacitor comprising a third terminal and a fourth terminal, the third terminal coupled to the node;
a semiconductor device coupled to the package substrate, the semiconductor device comprising a variable capacitor comprising a fifth terminal and a sixth terminal, the fifth terminal coupled to the node; and
wherein the package substrate comprises at least one metal layer coupled to the first terminal of the inductor and to the fifth terminal of the variable capacitor.
2. The tunable circuit package of claim 1 , wherein the passive device further comprises a passive-on-glass (POG) device.
3. The tunable circuit package of claim 1 , wherein the semiconductor device further comprises a low noise amplifier (LNA) circuit.
4. The tunable circuit package of claim 1 , wherein the semiconductor device further comprises an antenna switch module (ASM) coupled to the first terminal of the inductor and the ASM is configured to couple to an antenna.
5. The tunable circuit package of claim 4 , wherein:
the antenna is configured to receive a signal comprising a range of frequencies; and
the tunable circuit package is configured to reduce or prevent transmission of at least one frequency of the signal.
6. A tunable circuit package, comprising:
a first substrate comprising a first material;
an inductor comprising:
at least one first metal layer in the first substrate; and
a first terminal;
a first capacitor comprising:
at least one second metal layer in the first substrate; and
a second terminal coupled to the first terminal of the inductor;
a second substrate comprising a semiconductor material different than the first material of the first substrate;
a variable capacitor disposed in the second substrate, the variable capacitor comprising a third terminal coupled to the first terminal of the inductor; and
a package substrate comprising at least one metal layer coupled to the first terminal of the inductor and to the third terminal of the variable capacitor.
7. The tunable circuit package of claim 6 , wherein:
the package substrate comprises a first surface;
the first substrate is disposed on the first surface; and
the second substrate is disposed on the first surface.
8. The tunable circuit package of claim 6 , wherein the first material of the first substrate comprises glass.
9. The tunable circuit package of claim 6 , wherein the variable capacitor comprises a varactor.
10. The tunable circuit package of claim 6 , wherein the variable capacitor comprises a plurality of switched capacitors, each switched capacitor comprising:
a switch; and
a second capacitor.
11. The tunable circuit of claim 6 integrated into a radio frequency (RF) front end module.
12. The tunable circuit of claim 6 integrated into a device selected from the group consisting of: a set top box; an entertainment unit; a navigation device; a communications device; a fixed location data unit; a mobile location data unit; a global positioning system (GPS) device; a mobile phone; a cellular phone; a smart phone; a session initiation protocol (SIP) phone; a tablet; a phablet; a server; a computer; a portable computer; a mobile computing device; a wearable computing device; a desktop computer; a personal digital assistant (PDA); a monitor; a computer monitor; a television; a tuner; a radio; a satellite radio; a music player; a digital music player; a portable music player; a digital video player; a video player; a digital video disc (DVD) player; a portable digital video player; an automobile; a vehicle component; avionics systems; a drone; and a multicopter.
13. The tunable circuit package of claim 6 , further comprising a first acoustic resonator, comprising:
the inductor;
the first capacitor; and
a piezoelectric material disposed on the first substrate.
14. The tunable circuit package of claim 13 , further comprising:
a second acoustic resonator disposed on the first substrate, the second acoustic resonator comprising:
the piezoelectric material disposed on the first substrate; and
a fourth terminal coupled to the first terminal of the inductor.
15. The tunable circuit package of claim 14 , wherein:
the first acoustic resonator comprises a fifth terminal; and
the second acoustic resonator further comprises a sixth terminal coupled to the fifth terminal of the first acoustic resonator.
16. A method of manufacturing a tunable circuit package, comprising:
forming a first substrate comprising a first material;
forming an inductor comprising:
at least one first metal layer in the first substrate; and
a first terminal;
forming a first capacitor comprising:
at least one second metal layer in the first substrate; and
a second terminal coupled to the first terminal of the inductor;
forming a second substrate comprising a semiconductor material different than the first material of the first substrate;
forming a variable capacitor disposed in the second substrate, the variable capacitor comprising a third terminal coupled to the first terminal of the inductor; and
forming a package substrate comprising at least one metal layer coupled to the first terminal of the inductor and to the third terminal of the variable capacitor.
17. The method of claim 16 , further comprising:
disposing the first substrate on a first surface of the package substrate; and
disposing the second substrate on the first surface of the package substrate.
18. The method of claim 16 , wherein forming the first substrate comprising the first material further comprises forming a glass substrate.