Satellite communication transmitter with improved thermal management

21) A device, comprising a radiofrequency (RF) amplifier chip in thermal communication with a radiant cooling element, wherein the RF amplifier chip comprises an active layer disposed adjacent to a thermally conductive substrate separate from the radiant cooling element, wherein the thermally conductive substrate has a thermal conductivity greater than about 1000 W/mK, wherein:

• (i) the RF amplifier chip is configured to conduct heat to the thermally conductive substrate,
• (ii) the thermally conductive substrate is configured to conduct heat to the radiant cooling element, and
• (iii) the radiant cooling element is configured to radiate heat out of the radiant cooling element.

29) A method comprising generating a radiofrequency (RF) amplifier chip configured for thermal communication with a radiant cooling element, wherein the RF amplifier chip comprises an active layer disposed adjacent to a thermally conductive substrate separate from the radiant cooling element, wherein the thermally conductive substrate has a thermal conductivity greater than about 1000 W/mK, wherein:

• (i) the RF amplifier chip is configured to conduct heat to the thermally conductive substrate,
• (ii) the thermally conductive substrate is configured to conduct heat to the radiant cooling element, and
• (iii) the radiant cooling element is configured to radiate heat out of the radiant cooling element.

33) A method for using a radiofrequency (RF) amplifier chip, comprising:

• a) providing the RF amplifier chip in thermal communication with a radiant cooling element, wherein the RF amplifier chip comprises an active layer disposed adjacent to a thermally conductive substrate separate from the radiant cooling element, wherein the thermally conductive substrate has a thermal conductivity greater than about 1000 W/mK;
• and
• b) conducting heat (i) from the RF amplifier to the thermally conductive substrate, (ii) from the thermally conductive substrate to the radiant cooling element, and (iii) out of the radiant cooling element.

35) A method of heat transfer within a radiofrequency (RF) amplifier chip including an active layer disposed adjacent to a thermally conductive substrate, wherein the thermally conductive substrate has a thermal conductivity greater than about 1000 W/mK, wherein the RF amplifier chip is thermally coupled to a radiant cooling element, the method comprising:

• a) conducting heat from the active layer to the thermally conductive substrate;
• and
• b) conducting heat from the thermally conductive substrate to the radiant cooling element for radiation of heat out of the radiant cooling element.

37) A device, comprising a radiofrequency (RF) amplifier chip configured for thermal communication with a radiant element, wherein the RF amplifier chip comprises a first substrate comprising a first material disposed adjacent to a second substrate comprising a second material that is different than the first material, which second substrate is separate from the radiant element, wherein the second substrate has a thermal conductivity greater than about 1000 W/mK, and wherein (i) the first substrate is configured to conduct heat to the second substrate, and (ii) the second substrate is configured to conduct heat to the radiant element.