Articles by Harlan Howe

Published September 19, 2006 From: Chong Yik Lam, Agilent Technologies Dear Harlan, When I look at the signal flow diagram shown in some of the journal publications, the reflection coefficient for a two-port network is p. The transmission coefficient would become 1+p considering this is a lossless network. Should...

Published September 01, 2006 In an effort to better combine the editorial content of our magazine with our newly developed and retooled on-line presence, we have decided to expand Harlan's RF and microwave engineering advice into a monthly feature that appears in Microwave Journal. Harlan has selected one question...

Published September 7, 2006 In an effort to better combine the editorial content of our magazine with our newly developed and retooled on-line presence, we have decided to expand Harlan's RF and microwave engineering advice into a monthly feature that appears in Microwave Journal. Harlan has selected one question...

Published August 25, 2006 From: Melanie Barclay, Scientific Research Corp. Dear Harlan, I am familiar with four-port couplers, but I am having trouble understanding the operation of a four-port, 20 dB coupler with two inputs. The port connections are as follows: J1=main signal; J2=output from coupler; J3=terminated (50 ohms);...

Published August 14, 2006 From: Ky-Hien Do Dear Harlan, How do you build a coaxial balun? Dear Ky-Hien, In its simplest form a coaxial balun can be made from two quarter-wave sections of coaxial line. The unbalanced input is to one line. The outer conductors at this end are...

Published September 01, 2006 In an effort to better combine the editorial content of our magazine with our newly developed and retooled on-line presence, we have decided to expand Harlan's RF and microwave engineering advice into a monthly feature that appears in Microwave Journal. Harlan has selected one question...

Published July 25, 2006 From: SM Hassan, Virginia Tech Dear Harlan, How and why does the selection of an RF choke affect the proper operation of the amplifier in RF circuits? Dear SM, Chokes are used to separate RF signals from other circuit functions like bias networks. The degree...

Published July 10, 2006 In an effort to better combine the editorial content of our magazine with our newly developed and retooled on-line presence, we have decided to expand Harlan's RF and microwave engineering advice into a monthly feature that appears in Microwave Journal. Harlan has selected one question...

Published June 30, 2006 From: Jean Almira, Eudyna Devices Asia Singapore Dear Harlan, I would like to ask your advice regarding directional couplers. I am confused about backward wave couplers and forward wave couplers. I have read some articles: waveguide couplers in the forward direction (forward wave couplers) and...

Published June 7, 2006 From: Devendra Chitguppa, BEL Bangalore What is the relation between CW (unmodulated carrier power) and modulated carrier power in the case of BPSK, QPSK, 16QAM, 32QAM, 64QAM, 128QAM and 256QAM? Dear Devendra, The theoretical modulation losses for various schemes are a function not only of...