Dual mode satellite telephone with hybrid battery/capacitor power supply

• US 6,064,857 A
• Filed: 04/15/1997
• Issued: 05/16/2000
• Est. Priority Date: 04/15/1997
• Status: Expired due to Fees

• Current Assignee: Globalstar Incorporated
• Original Assignee: Globalstar Incorporated
• Inventors: Izadian, Jamal, Gallagher, Vijaya, Wiedeman, Robert A
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Kincaid, Lester G.
• Application Number:
  US08/834,239
• Time in Patent Office: 1,127 Days
• Field of Search: 455/127, 455/572, 455/573, 455/574, 455/126, 455/93, 455/552, 455/553, 455/343, 455/10, 455/12.1, 455/13.1, 455/13.4, 455/63, 330/297, 307/110, 375/216
• US Class Current: 455/127.4
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions

Abstract

A method for operating a satellite communications terminal (10) that transmits one of digital voice or data signals during a frame period. The terminal includes a transmitter and a receiver, the transmitter including an RF power amplifier. The method includes the steps of: (a) providing the terminal with a power source including a battery, a high energy density capacitor (HEDC), and a switching circuit for selectively coupling one or both to an output of the power source, the output of the power source being coupled at least to the RF power amplifier; (b) storing predetermined threshold values, including at least a data rate threshold value and a transmitter power level threshold value; (c) comparing at least one of a transmission rate and a transmission power level to be used during a next frame period to the stored data rate and power level threshold values; and (d) responsive to the comparison, controlling the switching circuit so as to select one or both of the battery and HEDC for coupling to the output of the power source. In a preferred embodiment the step of storing includes an initial step of receiving at least one of the data rate threshold value and the transmitter power level threshold value from a satellite that is linked to a terrestrial station. The step of storing further includes an initial step of inputting at least one of a mode flag and an on/off flag from a terminal user interface, and storing the inputted flag in a memory. In this case the step of comparing is responsive to the stored flags for selecting whether to connect only the battery, or only the HEDC, or both the battery and the HEDC in parallel to the output of the power source.

Claims

1. A communications terminal that periodically transmits information during transmission periods, comprising:

a transmitter;

a power source comprised of a battery and a capacitor;

a switching circuit coupled to said battery and said capacitor for selectively coupling one of (a) the battery alone, (b) the capacitor alone, and (c) both together in parallel to an output of said power source, said output of said power source being coupled at least to said transmitter; and

a controller, responsive to a transmission rate to be used during a next transmission period, for controlling said switching circuit so as to select either one or both together in parallel of said battery and capacitor for coupling to said output of said power source.

2. A communications terminal that periodically transmits information during transmission periods, comprising:

a transmitter;

a power source comprised of a battery and a capacitor;

a switching circuit coupled to said battery and said capacitor for selectively coupling one of (a) the battery alone, (b) the capacitor alone, and (c) both together in parallel to an output of said power source, said output of said power source being coupled at least to said transmitter; and

a controller, responsive to a transmitter power level to be used during a next transmission period, for controlling said switching circuit so as to select either one or both together in parallel of said battery and capacitor for coupling to said output of said power source.

3. A communications terminal that transmits one of digital voice or data signals during a transmission period, comprising:

a transmitter;

a power source comprised of a battery and a high energy density capacitor (HEDC);

a switching circuit coupled to said battery and said HEDC for selectively coupling one of (a) the battery alone, (b) the HEDC alone, and (c) both together in parallel to an output of said power source, said output of said power source being coupled at least to said transmitter;

a memory for storing predetermined threshold values, including at least a data rate threshold value and a transmitter power level threshold value;

a processor coupled to said memory, said processor comprising means for comparing a transmission rate to be used during a next transmission period to said data rate threshold value and for comparing a transmission power level to be used during said next transmission period to said power level threshold value, said processor being responsive to said comparing means for controlling said switching circuit so as to select one of (a) the battery alone, (b) the HEDC alone, and (c) both together in parallel for coupling to said output of said power source.

4. A satellite communications terminal that transmits one of digital voice or data signals during a frame period, comprising:

a transceiver comprising a transmitter and a receiver, said transmitter including an RF power amplifier;

a power source comprised of a battery and a high energy density capacitor (HEDC);

a switching circuit coupled to said battery and said HEDC for selectively coupling one of (a) the battery alone, (b) the HEDC alone, and (c) both together in parallel to an output of said power source, said output of said power source being coupled at least to said RF power amplifier;

a memory for storing predetermined threshold values, including at least a data rate threshold value and a transmitter power level threshold value; and

a controller coupled to said memory, said controller comprising means for comparing a transmission rate to be used during a next frame period to said data rate threshold value and for comparing a transmission power level to be used during said next frame period to said power level threshold value, said controller being responsive to said comparing means for controlling said switching circuit so as to select one of (a) the battery alone, (b) the HEDC alone, and (c) both together in parallel for coupling to said output of said power source.

5. A satellite communications terminal as set forth in claim 4, wherein said controller is further comprised of means, coupled to said receiver, for receiving at least one of said data rate threshold value and said transmitter power level threshold value, and for storing said received value in said memory.

6. A satellite communications terminal as set forth in claim 4, wherein said memory further stores a mode flag and an on/off flag, and wherein said comparing means is responsive to said flags for selecting whether to connect only said battery, or only said HEDC, or both said battery and said HEDC in parallel to said output of said power source.

7. A method for operating a satellite communications terminal that transmits one of digital voice or data signals during a frame period, the terminal including a transceiver comprising a transmitter and a receiver, the transmitter including an RF power amplifier, comprising steps of:

providing the terminal with a power source comprised of a battery, a high energy density capacitor (HEDC), and a switching circuit coupled to the battery and the HEDC for selectively coupling one of (a) the battery alone, (b) the HEDC alone, and (c) both together in parallel to an output of the power source, the output of the power source being coupled at least to the RF power amplifier;

storing predetermined threshold values, including at least a data rate threshold value and a transmitter power level threshold value;

comparing at least one of a transmission rate to be used during a next frame period to the stored data rate threshold value and a transmission power level to be used during the next frame period to the stored power level threshold value; and

responsive to the comparison, controlling the switching circuit so as to select one of (a) the battery alone, (b) the HEDC alone, and (c) both together in parallel for coupling to the output of the power source.

8. A method as set forth in claim 7, wherein the step of storing includes an initial step of receiving at least one of the data rate threshold value and the transmitter power level threshold value from a satellite that is linked to a terrestrial station.

9. A method as set forth in claim 7, wherein the step of storing includes an initial step of inputting at least one of a mode flag and an on/off flag from a terminal user interface, and storing the inputted flag in the memory.

10. A method as set forth in claim 9, wherein the step of comparing is responsive to the stored flags for selecting whether to connect only the battery, or only the HEDC, or both the battery and the HEDC in parallel to the output of the power source.