Articles by Harlan Howe

Published January 22, 2007 From: Alessandro Chianetta, STM Dear Harlan, Could you explain in easy words what dual carrier modulation (DCM) consists of? Dear Alessandro, I am not sure how easy these words are, since it is not an easy concept. DCM is used in OFDM-UWB (Orthogonal Frequency Division...

Published January 19, 2007 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 December 22, 2006 From: Chandrakanth Mariyappa, L&T Dear Harlan, How can I calculate the minimum detectable signal (MDS) of a receiver chain using a spectrum analyzer? What things need to be considered during the calculation? Dear Chandrakanth, The way to determine the MDS is to monitor the output...

Published December 8, 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 November 27, 2006 From: Mike O’Driscoll, student Dear Harlan, With regards to RF mixers, how would you define the sensitivity of a mixer? Is it possible to measure sensitivity? Dear Mike, I have always regarded sensitivity as the signal level needed for a minimum detectable signal above the...

Published November 13, 2006 From: Hadi Ghazian, Tarbiat Modares University Dear Harlan, How can I calculate and measure the maximum power capacity of a cylindrical waveguide operating in the TE11 mode? Dear Hadi, The power handling of waveguides is a function of dimensions, surface finish, conductivity, dielectric strength of...

Published October 25, 2006 From: Shi Bo, IZR Science Park Dear Harlan, How can you accurately measure noise figure on-chip using probes? Dear Shi, There are a number of commercially available probes and noise figure test sets that can be used to make measurements. However, the absolute noise figure...

Published October 13, 2006 From: Syed Abbas, College of Aeronautical Engineering Dear Harlan, How can I cater the power rating of an RF power combiner/splitter? Please specify the power rating of 250, 500 and 1000 W for a wideband application of 100 to 500 MHz. Dear Syed, There is...

Published October 06, 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 28, 2006 From: Qing Sun, University of Manchester Dear Harlan, What is the relationship between coupling factor and frequency in couplers and the bandwidth of a coupler as a function of even/odd mode impedance? Dear Qing, The bandwidth of a coupler is not a function of coupling...