We analyze the efficiency of organic pasture farming in Germany using data from 1994/95 to 2005/06. Five inputs and one output are analyzed by means of a stochastic frontier production function, allowing for heteroscedasticity and technical effects. Five sets of possible determinants of technical efficiency are considered in the model. These include: (1) farm structure and resources; (2) human capital and management capacities; (3) institutional choice; and (4) subsidies. To these factors that are commonly included in technical effects models, we add (5) a set of variables that capture localization and urbanization economies such as the share of organic farms in a region and the regional share of votes for the Green Party in recent elections. These regional effects are found to have a significant impact on the technical efficiency of organic farms. The evolution of efficiency on farms that are converting from conventional to organic farming is also analyzed.

Burst mode operation is proposed as an efficiency improving technique for power amplifiers. The core idea is to modulate the amplitude of the envelope signal into a series of square-wave pulses such that the width of the signal burst or the total amount of pulses are varied according to the envelope. The phase information is still contained by the timing of the pulses. This work presents the efficiency and linearity analysis of burst mode radio frequency (RF)/power amplifier (PA). In addition, the efficiency performance is compared when the burst mode RF power amplifiers (PA) is connected to a wideband load or a narrowband filter. It is shown that burst mode PAs are more efficient than the conventional Class B PAs. To achieve an even more favorable efficiency, a transmission line is inserted between the output of the switching RF PA and the filter to improve the filter's impedance characteristic. Additionally, the efficiency and linearity of the burst mode PA with and without transmission line has been studied and simulated thoroughly. To demonstrate the validity of the efficiency formulas and linearity considerations, a printed circuit board (PCB)-mounted burst mode PA using a laterally diffused metal oxide semiconductor (LDMOS) transistor was fabricated. Measurements show a peak efficiency of 78% and 28.8 dBm of output power.