Transmission power control device for a portable terminal

A device for controlling radio output of a mobile terminal, comprising:

• a transmission output amplifier for amplifying a signal to be transmitted, with an amplification factor decided by a first control signal;
• monitoring means, disposed on an output side of the transmission output amplifier, for monitoring power of a transmission output;
• a variable gain amplifier for amplifying the monitored transmission output, with an amplification factor being decided by a second control signal;
• detection means, with a diode as a main component, for detecting an output signal from the variable gain amplifier;
• differential amplification means for comparing an output of the detection means and a reference signal and amplifying a difference between the two signals so as to generate the first control signal;
• and
• control means for generating the second control signal and the reference signal,
• wherein the second control signal is adjusted to become a value for setting a gain of the variable gain amplifier so that a level of an output of the monitoring means falls within a range for which detection by the detection means is possible, and the reference signal is adjusted as a function of the second control signal;
• wherein the transmission signal amplification means is constructed of first amplification means and second amplification means which are arranged in series and which have their respective amplification ratios varied by means of applied control signals, with the first control signal being applied to the first amplification means and a third control signal from the control means being applied to the second amplification means;
• wherein the first amplification means is amplification means for amplifying a signal in an IF frequency range, while the second amplification means is amplification means for amplifying a signal in an RF frequency range,
• and the device for controlling radio output further comprises frequency conversion means disposed between the first amplification means and the second amplification means, for converting the signal in the IF frequency range to a signal in the RF frequency range.

A device for controlling radio output of a mobile terminal, comprising:

• transmission signal amplification means for amplifying an inputted transmission signal by an amplification factor decided by an applied first control signal;
• monitoring means for monitoring the transmission signal amplified by the transmission signal amplification means;
• monitoring signal amplification means for amplifying an output of the monitoring means by an amplification factor decided by an applied second control signal;
• detection means for detecting an output signal from the monitoring signal amplification means;
• differential amplification means for comparing a signal outputted by the detection means and a supplied reference signal and amplifying a difference between the two signals so as to generate the first control signal;
• and
• control means for generating the second control signal and the reference signal;
• wherein the control means decides the amplification factor of the monitoring signal amplification means so that a level of the output of the monitoring means is within a range which allows detection by the detection means;
• wherein the transmission signal amplification means is constructed of first amplification means and second amplification means which are arranged in series and which can have their respective amplification ratios varied by means of applied control signals, with the first control signal being applied to the first amplification means and a third control signal from the control means being applied to the second amplification means;
• and
• wherein the first amplification means is amplification means for amplifying a signal in an IF frequency range, while the second amplification means is amplification means for amplifying a signal in an RF frequency range, and the device for controlling radio output further comprises frequency conversion means, disposed between the first amplification means and the second amplification means, for converting the signal in the IF frequency range to a signal in the RF frequency range.