An intermittent microwave energy delivery system, comprising: a microwave energy source configured to provide a continuous microwave energy signal; an energy delivery network configured to intermittently transmit a portion of the continuous microwave energy signal; a first resistive load connected to ground configured to dissipate the microwave energy signal; and a switching network (740, 770) configured to switch the continuous microwave energy signal between the delivery network and the first resistive load, whereby the continuous microwave energy signal is time proportioned between the energy delivery network and the first resistive load, wherein the switching network further includes: a transfer switch; the switching network being further characterised by a variable attenuator configured to receive the continuous microwave signal from the microwave energy source, the variable attenuator including a second resistive load connected to a ground potential; and an amplifier, wherein the variable attenuator is configured to proportionate the continuous microwave signal from the microwave energy source between the second resistive load and the amplifier, and wherein the amplifier amplifies the microwave signal from the variable attenuator and supplies the amplified signal to the energy delivery network. a microwave energy source configured to provide a continuous microwave energy signal; an energy delivery network configured to intermittently transmit a portion of the continuous microwave energy signal; a first resistive load connected to ground configured to dissipate the microwave energy signal; and a switching network (740, 770) configured to switch the continuous microwave energy signal between the delivery network and the first resistive load, whereby the continuous microwave energy signal is time proportioned between the energy delivery network and the first resistive load, wherein the switching network further includes: a transfer switch; the switching network being further characterised by a variable attenuator configured to receive the continuous microwave signal from the microwave energy source, the variable attenuator including a second resistive load connected to a ground potential; and an amplifier, wherein the variable attenuator is configured to proportionate the continuous microwave signal from the microwave energy source between the second resistive load and the amplifier, and wherein the amplifier amplifies the microwave signal from the variable attenuator and supplies the amplified signal to the energy delivery network. a transfer switch; the switching network being further characterised by a variable attenuator configured to receive the continuous microwave signal from the microwave energy source, the variable attenuator including a second resistive load connected to a ground potential; and an amplifier, wherein the variable attenuator is configured to proportionate the continuous microwave signal from the microwave energy source between the second resistive load and the amplifier, and wherein the amplifier amplifies the microwave signal from the variable attenuator and supplies the amplified signal to the energy delivery network.