Noise canceling circuits
In some examples, an antenna module includes a ground plane, where the ground plane couples to a ground foil of an electronic device, an antenna coupled to the ground plane, and a noise canceling circuit disposed within a cutout of the ground plane.
1 . An antenna module, comprising:
a ground plane, the ground plane to couple to a ground foil of an electronic device;
an antenna coupled to the ground plane; and
a noise canceling circuit disposed within a cutout of the ground plane, wherein the noise canceling circuit comprises a resonating element.
2 . The antenna module of claim 1 , wherein the resonating element comprises:
a first resonating element to resonate in response to a first frequency range; and
a second resonating element coupled to the ground plane, the second resonating element to resonate in response to a second frequency range.
3 . The antenna module of claim 2 , wherein the noise canceling circuit comprises:
a resistor, a first end of the resistor coupled to the first resonating element and a second end of the resistor coupled to the ground plane;
an inductor, a first end of the inductor coupled to the first resonating element and a second end of the inductor coupled to the second resonating element; and
a capacitor, a first end of the capacitor coupled to the second resonating element and a second end of the capacitor coupled to the ground plane.
4 . The antenna module of claim 1 , wherein the noise canceling circuit comprises:
an inductor, a first end of the inductor coupled to the resonating element and a second end of the inductor coupled to a first end of a first switch;
a capacitor, a first end of the capacitor coupled to the resonating element and a second end of the capacitor coupled to a first end of a second switch; and
a tuner circuit including the first switch and the second switch.
5 . The antenna module of claim 4 , wherein the tuner circuit is to couple to a coaxial cable of the electronic device.
6 . The antenna module of claim 1 , wherein the noise canceling circuit is disposed on a non-conducting substrate within the cutout of the ground plane.
7 . The antenna module of claim 1 , wherein the resonating element has a length that is a half wavelength or a quarter wavelength of a frequency range of the antenna.
8 . A display device, comprising:
a chassis having a plastic portion and a metal portion, the chassis including an internal side and an external side;
a ground foil coupled to the metal portion of the internal side of the chassis;
an antenna coupled to the ground foil, the antenna disposed on the plastic portion of the internal side of the chassis; and
a noise canceling circuit coupled to the antenna, the noise canceling circuit disposed within a cutout of the ground foil, wherein the noise canceling circuit comprises a resonating element.
9 . The display device of claim 8 , wherein an antenna module comprises the antenna and the noise canceling circuit.
10 . The display device of claim 8 , wherein the noise canceling circuit comprises:
a filter having a first end coupled to the resonating element and a second end coupled to the ground foil.
11 . The display device of claim 10 , wherein the resonating element is to resonate in response to detection of a signal having a frequency, wherein in response to the frequency being below a cutoff frequency, the filter enables propagation of the signal, and wherein in response to the frequency being equivalent to or above the cutoff frequency, the filter disables propagation of the signal.
12 . The display device of claim 10 , wherein the resonating element is to resonate in response to detection of a signal having a frequency, wherein in response to the frequency being below a first cutoff frequency and above a second cutoff frequency, the filter enables propagation of the signal, and wherein in response to the frequency being equivalent to or above the first cutoff frequency or equivalent to or below the second cutoff frequency, the filter disables propagation of the signal.
13 . The display device of claim 10 , wherein the filter is a low-pass filter, a high-pass filter, a band-pass filter, or a band-stop filter.
14 . The display device of claim 8 , wherein the antenna and the noise canceling circuit are disposed behind a display panel of the display device.
15 . The display device of claim 8 , further comprising a controller coupled to the noise canceling circuit, wherein the controller controls switches of the noise canceling circuit in response to a detected frequency.
16 . An electronic device, comprising:
a ground foil coupled to an internal, metal portion of a chassis of the electronic device;
an antenna having a ground coupled to the ground foil, the antenna disposed on an internal, plastic portion of the chassis; and
a noise canceling circuit comprising:
a resonating element;
a filter having a first terminal and a second terminal, the first terminal coupled to the resonating element; and
a switch coupled to the ground foil;
wherein the electronic device is to:
detect a frequency of the resonating element; and
in response to the frequency, cause the second terminal to couple to a second end of the switch.
17 . The electronic device of claim 16 , wherein the filter is a first filter and the switch is a first switch, and the noise canceling circuit comprising:
a second filter having a third terminal and a fourth terminal, the third terminal coupled to the resonating element,
a second switch coupled to the ground foil and the first end of the first switch, and
wherein the second switch is to, in response to the frequency, cause the fourth terminal to decouple from a second end of the second switch.
18 . The electronic device of claim 17 , wherein the electronic device is to:
detect a second frequency of the resonating element; and
in response to the second frequency, cause the fourth terminal to couple to the second end of the second switch and the second terminal to decouple from the second end of the first switch.
19 . The electronic device of claim 17 , wherein the electronic device is to:
detect a third frequency of the resonating element; and
in response to the third frequency, cause the fourth terminal to couple to the second end of the second switch and the second terminal to couple to the second end of the first switch.
20 . The electronic device of claim 17 , wherein the electronic device is to:
detect a fourth frequency of the resonating element; and
in response to the fourth frequency, cause the fourth terminal to decouple from the second end of the second switch and the second terminal to decouple from the second end of the first switch.