Modem card with balanced antenna
View Patent ↗A cellular modem card that conforms to a PCMCIA standard includes a balanced antenna. The balanced antenna minimizes susceptibility to limited available ground plane and limited ground connections between the modem card and a host device, such as laptop computer. The balanced antenna may be a dipole antenna, loop antenna, capacitively loaded antenna, or any other suitable balanced antenna.
1. A modem card comprising:
a connector having pin configuration in accordance with a Personal Computer Memory Card International Association (PCMCIA) standard;
electronics connected to the connector; and
a balanced antenna connected to the electronics, the balanced antenna comprising a transformer loop having a balanced feed interface and a capacitively-loaded loop radiator coupled to the transformer loop.
2. The modem card of claim 1 , wherein electronics comprise a cellular transceiver.
3. The modem card of claim 2 , wherein the balanced antenna is a dipole antenna.
4. The modem card of claim 1 , wherein the capacitively-loaded loop radiator is a balanced radiator.
5. The modem card of claim 1 , wherein the capacitively-loaded loop radiator comprises:
a quasi loop with a first end section and a second end section; and
a bridge section interposed between the quasi loop first and second end sections.
6. The modem card of claim 5 , wherein the bridge section is an element selected from the group including a dielectric gap capacitor and a lumped element capacitor.
7. The modem card of claim 5 wherein the quasi loop first end section comprises a portion formed parallel to a second end section portion and wherein the bridge section is a dielectric gap capacitor formed between the parallel portions of the first and second end sections.
8. The modem card of claim 5 , wherein the transformer loop has a radiator interface and wherein the quasi loop has a transformer interface coupled to the transformer loop radiator interface.
9. The modem card of claim 8 , wherein the transformer loop has a first perimeter; and, wherein the quasi loop has a second perimeter with at least a portion of the second perimeter in common with the first perimeter.
10. The modem card of claim 9 , wherein the transformer loop has a rectangular shape with a first side and wherein the quasi loop has a rectangular shape with the first side.
11. A cellular modem card comprising:
a connector having pin configuration in accordance with a Personal Computer Memory Card International Association (PCMCIA) standard;
electronics connected to the connector and comprising a cellular transceiver; and
a balanced antenna connected to the cellular transceiver, the balanced antenna comprising a transformer loop having a balanced feed interface and a capacitively-loaded loop radiator coupled to the transformer loop.
12. The cellular modem card of claim 11 , wherein the
balanced capacitively-loaded loop radiator comprises:
a quasi loop with a first end section and a second end section; and
a bridge section interposed between the quasi loop first end section and the second end section.
13. The cellular modem card of claim 12 , wherein the transformer loop has a radiator interface and a first perimeter and wherein the quasi loop has a transformer interface coupled to the transformer loop radiator interface, the quasi loop having a second perimeter with at least a portion of the second perimeter in common with the first perimeter.
14. A cellular modem card comprising:
a housing having a form conforming to a Personal Computer Memory Card International Association (PCMCIA) standard;
a connector having pin configuration and a form in accordance with the PCMCIA standard secured to the housing;
electronics connected to the connector and comprising a cellular transceiver; and
a balanced antenna connected to the cellular transceiver, the balanced antenna comprising a transformer loop having a balanced feed interface and a capacitively-loaded loop radiator coupled to the transformer loop.
15. The cellular modem card of claim 14 , wherein the
balanced capacitively-loaded loop radiator comprises:
a quasi loop with a first end section and a second end section; and
a bridge section interposed between the quasi loop first end section and the second end section.
16. The cellular modem card of claim 15 , wherein the bridge section is an element selected from the group including a dielectric gap capacitor and a lumped element capacitor.
17. The cellular modem card of claim 15 wherein the quasi loop first end section comprises a portion formed parallel to a second end section portion and wherein the bridge section is a dielectric gap capacitor formed between the parallel portions of the first and second end sections.
18. The cellular modem card of claim 15 , wherein the transformer loop has a radiator interface and wherein the quasi loop has a transformer interface coupled to the transformer loop radiator interface.
19. The cellular modem card of claim 18 , wherein the transformer loop has a first perimeter; and,
wherein the quasi loop has a second perimeter with at least a portion of the second perimeter in common with the first perimeter.
20. The cellular modem card of claim 19 , wherein the transformer loop has a rectangular shape with a first side and wherein the quasi loop has a rectangular shape with the first side.